1. Introduction
The ACR ResQLink 400 is a compact, buoyant, GPS-enabled Personal Locator Beacon (PLB) designed to provide a direct link to rescue services in an emergency. When activated, it transmits a powerful 406 MHz distress signal to the Cospas-Sarsat satellite system, along with your precise GPS location, alerting search and rescue efforts worldwide. This device is intended for use in outdoor emergencies across various activities including hiking, hunting, boating, and fishing.

Image: The ACR ResQLink 400 Personal Locator Beacon, a compact, bright yellow and clear device.

Image: The ResQLink 400 attached to a backpack during a hike, demonstrating portability.
2. Key Features
- No Subscription Required: Provides peace of mind with no ongoing fees for distress signaling.
- 406 MHz Distress and Homing Signals: Transmits powerful alerts to rescuers, ensuring quick identification of your location.
- LED Strobe and Infrared Strobe: Ensures maximum visibility in low-light and nighttime conditions for easier detection by rescuers.
- Global Coverage / Cospas-Sarsat / MEOSAR: Offers worldwide rescue capabilities via international satellite systems.
- GPS and Galileo GNSS: Ensures precise location tracking for efficient and timely rescue operations.
3. Setup and Registration
Before using your ResQLink 400, it is critical to register your beacon with the appropriate national authority. In the United States, this is the National Oceanic and Atmospheric Administration (NOAA). Registration is free and mandatory. It provides search and rescue forces with vital information about you and your vessel/activity, which can significantly aid in a rescue operation.
For detailed activation instructions, please refer to the video below:
Video: ACR ResQlink 400 + 425 Activation Guide. This video demonstrates the steps to activate your Personal Locator Beacon in an emergency.
Initial Registration Steps:
- Visit the official beacon registration website for your country (e.g., NOAA for USA).
- Locate your beacon's Unique Identifier Number (UIN) or Hex ID, typically found on the device label.
- Complete the online registration form with accurate personal and emergency contact information.
- Keep your registration information up-to-date, especially if your contact details or emergency contacts change.
4. Operating the ResQLink 400 in an Emergency
The ResQLink 400 is designed for simple, rapid deployment in life-threatening situations. Follow these steps carefully:
- Deploy the Antenna: Slide the antenna cover up and extend the antenna fully. Ensure it is positioned at a 90-degree angle to the beacon and has a clear view of the sky for optimal satellite reception.
- Activate the Beacon: Press and hold the red "ON" button for approximately 2 seconds until the red LED light begins to flash. The device will start acquiring GPS coordinates and transmitting the distress signal.
- Confirm GPS Acquisition: Once GPS coordinates are acquired, the red LED will turn green, indicating a successful position fix. The strobe light will also begin to flash.
- Maintain Position: Leave the beacon in an open area with an unobstructed view of the sky. Do not turn it off until rescue personnel confirm your safety.

Image: A person holding the ACR ResQLink 400 Personal Locator Beacon on a boat, demonstrating its use in a marine environment.
5. Self-Test Procedure
Regular self-testing ensures your ResQLink 400 is functioning correctly. Perform a self-test monthly or before any extended trip.
Video: ACR ResQlink 400 + 425 Self-Test Guide. This video provides instructions on how to perform a self-test on your Personal Locator Beacon.
Steps for Self-Test:
- Deploy Antenna: Slide the antenna cover up and extend the antenna fully.
- Initiate Self-Test: Press and hold the "T" (Test) button for approximately 2 seconds.
- Observe LEDs: The green LED will flash once, followed by a second green LED flash. If you have the "View" model, the display will confirm "SELF TEST PASS".
- Important Note: During the self-test, ensure you do not touch the antenna. Holding the antenna can interfere with the test and potentially cause it to fail.
If the self-test fails (e.g., red LED flashes, no display message, or "FAIL" message), consult the troubleshooting section or contact ACR support.
6. Maintenance and Care
- Battery Life: The ResQLink 400 uses 2 Lithium Metal batteries (included). Check the expiration date on the device. Batteries must be replaced by an authorized service center.
- Cleaning: Clean the device with a damp cloth. Do not use harsh chemicals or abrasive cleaners.
- Storage: Store the beacon in a cool, dry place, away from direct sunlight and extreme temperatures. Ensure the antenna is stowed correctly to prevent damage.
- Inspection: Periodically inspect the device for any signs of damage, cracks, or corrosion. Ensure the antenna is intact and the buttons are functional.
7. Troubleshooting
| Issue | Possible Cause | Solution |
|---|---|---|
| Self-Test Fails (Red LED) | Antenna not deployed correctly, low battery, internal fault. | Ensure antenna is fully extended and not obstructed. Check battery expiration. If issue persists, contact ACR support. |
| No GPS Acquisition during activation | Obstructed view of sky, device not stationary. | Move to an open area with a clear view of the sky. Keep the device stationary during activation. |
| Device does not turn on | Depleted or expired battery. | Check battery expiration date. Contact ACR support for battery replacement. |
8. Specifications
- Product Dimensions: 4.52 x 2.03 x 1.49 inches
- Item Weight: 5.3 ounces
- Item Model Number: PLB-400
- Batteries: 2 Lithium Metal batteries (included)
- Special Feature: Waterproof
- Connectivity Technology: IR
- Supported Application: GPS
- Material: Plastic
- Date First Available: March 13, 2019
- Manufacturer: ACR Electronics, Inc.
9. What's in the Box
- ACR ResQLink 400 Personal Locator Beacon
- Belt Clip
- PFD Oral Inflation Tube Clip
- Attachment Strap
10. Warranty and Support
ACR Electronics, Inc. stands behind the quality and reliability of its products. For specific warranty details, service, or technical support, please refer to the official ACR website or contact their customer service directly.
Visit the ACR Store on Amazon for more information and product offerings.
11. Important Safety Information
The ACR ResQLink 400 is a critical safety device. It is subject to regulations by various authorities, including Cospas-Sarsat and the FCC. Always ensure your device is properly registered and maintained according to local and international guidelines. This device is intended for emergency use only. False activation can result in penalties.
Legal Disclaimer: Cospas-Sarsat, FCC





