This is a marine rescue-oriented underwater locating beacon designed primarily for Voyage Data Recorder (VDR) protective capsules on ships and similar marine craft. Its main purpose is to help locate wreckage and data capsules underwater after an accident by emitting an acoustic signal that search equipment can detect.

This type of underwater locating device is typically fitted to VDR/S-VDR data protective capsules on commercial vessels. In the event of a sinking or serious maritime accident, the beacon helps search and rescue teams locate key blackout boxes and other equipment underwater by transmitting an acoustic signal detectable with sonar receivers.