A timer based explosive that attracts creatures by using high frequencies.
The B.O.W. Decoy is a special grenade that appears in Resident Evil: Revelations. They were manufactured as early as 2005. Upon throwing a Decoy, it will emit a sound that attracts certain types of B.O.W.s and will explode after a short period of time. They attract everything except Hunters and Scarmigliones.
Only BSAA operatives are in possession of Decoys, making it a possibility that it was designed and created by the BSAA.
You and your partner will never take damage or be killed by an explosion from grenade-type weapons. However, a Shock grenade can stun you and your partner temporarily if you're caught within the blast radius.