This will shorten the Action and reset faster than stock. Some Glock's may require the shortening of the tab, function without the need of trimming in 99% of all Glock's tested. This 4.5lb Semi-Drop-In Combatives Application Trigger (CAT) connector offers a smooth trigger action insuring the muzzle stays on target during a critical stress, pandemonium filled fight. The Ghost C.A.T. gives you cat like response to the lethal situations. Why a semi Drop-In? We