The ACR(r) 406 MHz MicroFix(r) GPS personal locator beacon is a small, lightweight and function rich PLB that alerts Search and Rescue to your precise location in an emergency. It transmits on 406 MHz (COSPAS-SARSAT) with your registered, unique, digitally-coded distress signal, and 121.5 MHz (SAR homing frequency). The exclusive built-in GPS technology is finely tuned for optimum performance.