The Present Arms 1911 Fixture Block fits the Present Arms 1911 Armorer Plate to allow the armorer to fit and dress all parts of the 1911 handgun. Check Trigger - Sear fit Holds Grip safety to dress trigger bow interface Hold Thumb safety to dress for plunger interface Hold Thumb safety for sear interface inspection Hold Frame for ease of sear & disconnect installation Mfg: Present Arms Inc