Rage X-treme shock collars prevent the blades on your Rage X-treme broadhead from prematurely deploying if you happen to bump your arrow or broadhead while on stand or stalking. Shock collars are designed to break upon impact and will need to be replaced after each shot. Inspect the shock collar for any damage prior to use to ensure proper function. These collars are compatible with all X-treme, SS, 2 Blades with SC Technology, & Hypodermic Standard broadheads. Approximate quantity is 15-20 per package.