The RECCO® Rescue System is a two-part system. Manufactures attach a small Band-Aid-sized reflector (sometimes called a chip) into clothing, boots, helmets, Ortovox avalanche transceivers, etc. The reflector is a passive device and does not require batteries or any user attention. A special detector, which is used by professional rescuers, transmits a signal that is reflected back to the detector. The system is analogous to submarine sonar—the detector sends a signal that bounces off the chip and is received by the detector.
These special detectors are used by more than 700 ski areas and search and rescue teams. The RECCO detector is a worthy addition to the professional's search arsenal, but it is not intended to replace avalanche transceivers. Even more so than avalanche transceivers, becoming proficient with a RECCO detector requires practice.
The RECCO system can sometimes detect other electronic devices, such as a cell phone or two-way radio, at very short distances. I have occasionally picked up a signal from electronic devices when training with a RECCO detector, but I have not been able to locate a victim's electronics during an actual search.
Newer RECCO detectors also receive the 457 kHz signal from avalanche transceivers, but without displaying direction or distance indicators. That's still very helpful for a professional rescuer, because one rescuer can search for an avalanche transceiver and RECCO reflector simultaneously.