The Extreme Shock Collar by Rage prevents the blade on your Rage Extreme and Hypodermic Standard broadheads from prematurely deploying. If you happen to bump your arrow or broadhead while on a stand or stalking, the Extreme Shock Collar keeps the blade secure and steady. Shock collars are designed to break upon impact so will need to be replaced after each shot. Inspect for any damage prior to use to ensure proper function. Comes as a single Extreme Shock Collar.