■ Product Information

  • ASR-L251G
  • GUN-Type
  • AsLock

iOS / Android / Windows.
This GUN-Type combination model reads and writes RAIN UHF RFID tags and scans 2D/1D barcodes all-in-one.
With a max output power of 30dBm (1 Watt) this has a long read range for RAIN UHF RFID tags from 0 to 40 feet (0~12m), depending on the tags and environment. The linear antenna means you can utilize the 60° aperture to reading in a more directional fashion than most and it directs that full watt of power in front of it, so it can penetrate deeper into pallets, etc.
Connectivity is a breeze because the device is hard-wired. Contained within the "AsLOCK" is a magnetic USB connection ("Magconn") that allows you to connect and go instantly, without the headaches or bottlenecks of Bluetooth pairing. More than any spec-sheet, once you hold the AsReader device in your hands you will instantly feel and realize the significantly higher quality of AsReader.
Designed in Japan. Made in South Korea.


Model Name ASR-L251G-XX
RFID Spec ISO 18000-63 (Formerly known as: ISO 18000-6 Type C) / EPC Class1 Gen2
Bandwidth Japan:916-921Mhz
North America:902-928Mhz
Brazil:902-908, 915-928Mhz
Output power 1W (30dBm) 5dBm~30dBm: adjustable per 1dBm
Reading distance 0~12m ※1
Reading speed ≥1000 pieces/sec ※2
Polarization characteristics Linearly polarized antenna
Function Read / Write / Lock / Kill
Barcode Scan Engine CMOS Sensor
Reading range ■Barcode resolution : Distance to the front of the device
100% U.P.C. : 46 mm ‒ 419 mm
CODE 39 - 5 mil : 64 mm ‒ 163 mm
CODE 39 - 10 mil : 28 mm ‒ 338 mm
PDF417 - 6.7 mil : 46 mm ‒ 185 mm
Data Matrix - 10 mil : 53 mm ‒ 203 mm
Reading angle Pitch: ±45° Roll: 360° Skew motion: ±60° ※3
Reading code ■1D: UPC/EAN/JAN, GS1 DataBar, Code 39, Code 128, Code 32, Code 93, Codabar/NW7, Interleaved 2 of 5,
 Code 2 of 5, Matrix 2 of 5, MSI, Telepen, Trioptic, China Post
■2D Stacked: PDF417, MicroPDF417, GS1 Composite
■2D Matrix: Aztec Code, Data Matrix, QR Code, Micro QR Code, MaxiCode, Han Xin Code
■Postal: Intelligent Mail Barcode, Postal-4i, Australian Post, British Post, Canadian Post, Japanese Post,
 Netherlands (KIX) Post, Postnet, Planet Code
Light sources Illumination: White LED, Aiming: Red Laser (Class 2)
Power Source Battery Capacity Built -in rechargeable lithium-ion battery 3400mAh
Continuous operation time ■RFID
About 11 hours (scan every 5 s; 30 s standby time)
About 8 hours (scan every 10 s; 30 s standby time)

About 32 hours or 20,000 times (scan every 5 s)
Power Source USB-C cable & Magnetic suction header with 8mm D. ※4
Charging time About 3.5 hours (Built-in battery)
Key input Trigger, Mode button, Power button
Communication Interface USB
Appearance Dimensions(D)x(W)x(H) 196x64x145m
Weight (with Battery) About 370g
Material PC (Polycarbonate)
Case color White/Gray
LED Power indicator: red/green Mode indicator: white
Environment Operating environment -10℃ ~ 45℃
Charge environment 0℃ ~ 45℃
Storage environment -20℃ ~ 60℃ (A month)
Operation humidity 20~85% RH
Storage humidity 10~95% RH
IP rating IP54 compliance (only when connected to AsLock)
Anti-drop (Six -sided, 4 edge, once each) 1.5m ※5
Certificates TELEC / FCC / CE / SRRC / ANATEL / RoHS
Bundled items USB-C cable & Magnetic suction header with 8mm D

※ 1 It depends on the type of RF tag and operating environment.
※ 2 It depends on the settings and operating environment.
※ 3 It depends on the barcode type.
※ 4 Use a 5V3A output charging adapter for charging.
※ 5 This product only.

  Version Update date Size  
User manual Version 1.2 25 Oct. 2022 3.5MB Download(PDF)
iOS DemoAPP User Manual 1.1 24 Mar. 2022 787KB Download(PDF)
Barcode Setting Manual Version 1.8 20 Jun. 2022 4.2MB Download(PDF)
Datasheets     117KB Download(PDF)

SDK / Sample Application

■License Agreement

Please read the License Agreement below before downloading.

Licence Agreement for AsReader SDK

Please read carefully before using the Software Development Kit "AsReader SDK" (hereafter "SDK") that is developed and offered by the Company (Asterisk Inc.).

In offering the SDK we require you to agree to the Terms of Use below as a condition of use.
Please read the Terms of Use below before installing the software.By installing the SDK you agree to the Terms of Use below. If you cannot agree with the Terms of Use below, please refrain from using the SDK.

【Terms of Use】

Article 1: Purpose of these Terms of Use

The purpose of these Terms of Use is to determine the common Terms of Use for the SDK that is offered by the Company to the users of the SDK as they are determined in the next Article.

Article 2: Definitions

  1. For these Terms of Use, "User" is defined as an individual who develops software applications and uses the SDK.
  2. For these Terms of Use, "Target Product" is defined as the AsReader Development SDK that is developed by the Company and publicly available both free of charge or for a fee.
  3. For these Terms of Use, "Library" is defined as the program developed by the Company which has the control function over the Target Products, which includes the SDK.
  4. For these Terms of Use, "API Specification Document" is defined as the document in which the specifications of the linkage function with the external program "Library", which includes the SDK are registered.
  5. For these Terms of Use, "Sample Program" is defined as a source code format program that is developed by the Company and which has a linkage function with the Library which includes the SDK, which the Company provides to the User as a sample when they are developing a user program.
  6. For these Terms of Use, "Modification Program" is defined as a program created by a User based on Article 3, Paragraph 2, Item (2).
  7. For these Terms of Use, "User Software" is defined as the software developed by the User and that has the control function over the Target Products.
  8. For these Terms of Use, "End User" is defined as the individual who uses the User Software.

Article 3: Licence of Use

  1. The Company grants free use of the information described in the API specifications worldwide for the purpose of implementing the development and improvement of User Software by Users.
  2. The Company grants the User the following worldwide rights regarding the Library and Sample Programs free of charge:
    1. The right to duplicate the Library and Sample Programs to the User's computer for the purpose of developing User Software.
    2. The right to alter the Sample Program for the purpose of developing User Software, or to rely on the Sample Program to develop other programs.
    3. The right to incorporate the following programs into user software:
      ① Library
      ② Sample Program
      ③ Modification Program
    4. The right to reproduce the User Software and to provide it to the End User by way of transferring (regardless of whether a fee is charged), lending, or public transmission.
    5. The right to license the use of the User Software that is based on the preceding number, which they provided to the End User.
  3. Article 4: Licence Period

    The licence period of the licence described in the preceding article (hereafter: "This Licence") shall be one year from the time the User agrees to these Terms of Use.
    However, unless declared otherwise by either the Company or the User up to 30 days prior to the expiration of such period, This Licence shall be renewed for one year under the same conditions.

    Article 5: Prohibited Acts

    The User shall not, with respect to the Target Software and the SDK, perform any of the following acts:

    1. Link User Software which has the control function over the Target Product with the Target Software using a method different from that described in the API Specification Document.
    2. Use the information described in the API Specification Document or the Sample Program for purposes other than the matters stipulated in the items of Article 3 of these Terms of Use.
    3. Use the information described in the API Specification Document to reverse engineer, or have a third party reverse engineer, the Target Software (which includes, but is not limited to, modification, reverse compiling and disassembling).

    Article 6: Support by the Company

    If the User needs support with the API Specification document or the content of the Sample Programs, or with the development of User Software, the Company is able to provide this support to the User for a fee.
    Furthermore, the contents and conditions of such support shall be determined in a separate contract to be signed by both the User and the Company.

    Article 7: Attribution of Rights

    1. All of the intellectual property rights such as industrial property rights, copyrights, trade secrets etc. (hereafter: "intellectual property rights") pertaining to the Target Software, API Specification Document, Library and Sample Program belong to the Company and will not be transferred to the User with the conclusion of these Terms of Use or the delivery of the API Specification Document.
    2. All of the intellectual property rights pertaining to the Modification Program belong to the User. However, concerning the Modification Program, the Company will continue to have the rights of the original author against the secondary work as specified in Article 28 of the Japanese Copyright Law .
    3. All of the intellectual property rights pertaining to the User Software belong to the User.

    Article 8: Scope of responsibility of the Company

    1. For API Specification Document, the Library and the Sample Program, the Company does not guarantee that there are no errors in them, that the content of them will be useful to the User's business or that they will work properly in the User Software, nor does the Company give guarantees on the API Specification Document and the Sample Program, including whether the information in them infringes on the rights of third parties.
    2. The Company is not liable for any damages (including, but not limited to, profit loss, suspended business, loss of business information and other financial damages) to the User due to the use of the information in the API Specification document, or from the use or inability to use the User Software that was created with the incorporation the Library, Sample Program or Modification Program.
    3. The Company is not responsible for the User Software, such as its functioning (including the control function of the Target Product in the User Software, the same shall apply hereafter), its quality or its usefulness to the End User, and Company disclaims any responsibility and will not respond to any enquiries from the End Users or other third parties, bug fix requests and other complaints, and objections or request etc. (hereafter "requests etc.") regarding the User Software.

    Article 9: Termination

    1. When the User falls under any of the following categories, the Company may without notice immediately cancel all or part of this License.
      1. The User fails to fulfill any obligations arising from these Terms of Use, and regardless of being informed of this by the counterparty and being given a reasonable time frame, continues to do so.
      2. The User commits fraud, or interferes with the performance of the counterparty's professional duties.
      3. The User is seized, provisionally seized, or receives a temporary injunction, or the User petitions for bankruptcy, for voluntary liquidation procedures or for corporate reorganization procedures, or the User petitions to start civil rehabilitation proceedings, or the User enters liquidation.
      4. The User decides to terminate, or the User wishes to transfer all or a significant part of the business to a third party.
      5. The User damages the credibility and honour of the company, or acts in a way that makes the Company lose trust in the User.
      6. When downloading the SDK, the User finds that the information offered by the Company contains false information.
    2. The Company shall be able to claim compensation from the User for damages to the Company because the User falls under any of the categories in the preceding paragraph.

    Article 10: Obligations after contract termination

    Upon termination of this License, the User shall immediately dispose of any API Specification documents, Libraries, Sample Programs and Modification Programs, and any copies thereof.

    Article 11: Survival Clause

    Even if this License is terminated, Articles 5, 6, 7, 10, 12 and 13 of these Terms of Use will remain in effect.

    Article 12: Prohibition of transfer of receivables / liabilities

    The Company and the User shall not transfer all or part of the rights or obligations under these Terms of Use to a third party without obtaining prior consent from the other party.

    Article 13: Dispute resolution

    In the event litigation is needed to resolve a dispute arising from these Terms of Use, the Company and the User shall in the first instance be subject to the exclusive jurisdiction of the Tokyo District Court .

    Version Update date Size  
Objective-C/Swift SDK 3.1.0 01 Mar. 2024 1MB Download(ZIP)
Objective-C Sample 4.1.3 27 May. 2024 3.1MB Download(ZIP)
Objective-C SDK Reference Guide V1.3 08 Apr. 2022 569KB Download(PDF)
Swift Sample 2.2.0 31 Mar. 2022 4.2MB Download(ZIP)
Cordova SDK (Includes AsRing SDK) 2.0.0 01 Oct. 2020 2.4MB Download(ZIP)
Sample 2.0.0 01 Oct. 2020 10.2MB Download(ZIP)
( for iOS )
SDK 2.8.0 31 Mar. 2022 2.1MB Download(ZIP)
Sample 2.5.0 31 Mar. 2022 4.5MB Download(ZIP)
( JAVA )
SDK (AsRing SDK not needed) 1.7.7 09 Feb. 2024 448KB Download(ZIP)
Sample 1.5.7 09 Feb. 2024 11.7MB Download(ZIP)
Windows (C#) SDK 1.0.0 09 Jun. 2022 184KB Download(ZIP)
Sample 1.0.0 09 Jun. 2022 553KB Download(ZIP)
.NET MAUI (for .NET 7)
SDK 1.7.7_1.0.0 04 Apr. 2024 724KB Download(ZIP)
Sample 1.0.0 04 Apr. 2024 943KB Download(ZIP)
.NET MAUI (for .NET 8)
SDK 1.7.7_1.0.0 04 Apr. 2024 718KB Download(ZIP)
Sample 1.0.0 04 Apr. 2024 938KB Download(ZIP)
.NET MAUI (for .NET 7)
SDK 3.1.0_1.0.0 30 Apr. 2024 2.5MB Download(ZIP)
Sample 1.0.0 30 Apr. 2024 2.8MB Download(ZIP)
.NET MAUI (for .NET 8)
SDK 3.1.0_1.0.0 30 Apr. 2024 2.5MB Download(ZIP)
Sample 1.0.0 30 Apr. 2024 2.8MB Download(ZIP)
■AsRingAccessory SDK
    Version Update date Size  
Objective-C/Swift SDK 2.4.0 01 Mar. 2024 440KB Download(ZIP)
( for iOS )
SDK 2.2.0 01 Oct. 2020 910KB Download(ZIP)


  Version Update date Size  
FW 1.9.01 01 Mar. 2024 53KB Download(ZIP)
FW Update for Windows PC 27 May. 2020 84KB Download(ZIP)

To the developers using AsReader

Please check the description of the following links page.
The Mfi registration application if necessary also thank you from the following link page.

To confirm the details

●iPhone®, iPad® and iPod touch® are registered trademarks of Apple® Inc.
●All other trademarks are property of their respective owners.