We are born explorers. The SOUND GRENADE helps us explore with confidence. It is an ultra-compact personal alarm, small in size but big in sound. Once you pull the pin, this personal alarm emits a 120 decibel (ambulance-level) alarm. The siren will sound continuously for 30 minutes unless pin is returned to device. INCLUDED: Battery and Metal Carabiner. As seen on NBC, this is the original Sound Grenade by ROBOCOPP. Beware of low-quality imitations.