The Universal Trigger Lock by Allen is a simple and effective lock that fits most handguns or revolvers. To install, place one side of the trigger lock on one side of the trigger with the post behind the trigger and the second on the other, then use the included key tool to secure the security screw into the lock.Features :Fits Most Handguns or RevolversHeavy-DutyMade From Durable CompositeEasy to Install