M35 Beacon

The is a emergency beacon used by UNSC forces, replacing the older generation M32 Beacon. The M35 Beacon utilises a high power meta-material antennae with a extremely large range, rendering it useful for missions deep behind enemy lines or in deep space. The beacon is housed in a ruggerdized, bullet proof casing with reinforced single-quartz crystal screen and hardened keypad. The beacon creates a heavily encrypted narrow-ban communications link between a unit and the WARNET emergency networks, no matter the distance to other units, and allows them to request emergency dust-offs or call for an emergency MEDEVAC. The Beacon's transmissions act as a two way hot link straight to theatre commands and ground forces and is virtually impossible to jam, back-hack or decrypt. 
Beacons are often deployed by infantry forces when they are in danger of being over run, or have taken significant casualties, or used by special forces when they call for dust-off following a mission (whether it was completed or compromised.). The Beacon is clipped onto standard infantry webbing and can be adhered to walls or simply tossed to the ground, where it acts as a homing beacon. After the beacon activated, it had a life span of 24 hours, after which it purged it's own systems and deactivated, preventing it's use by enemy forces. Systems slagged themselves using a small thermate charge should the battery run out, or the beacon be tampered with while active.