Upper Parts Kit (UPK) for Glock 19 - Gen 5. These are great for completing your custom slide. All parts are from US manufacturer. All Parts are made to the highest tolerance to the original specification. These parts are Gen 5 specific and not compatible with any other Gens.Features :Firing Pin SpringFiring Pin Spacer SleeveSpring Cups (2-Pack)Firing Pin Safety NitrideFiring Pin Safety SpringExtractor Depressor Plunger NitrideExtractor Depressor Plunger SpringSpring Loaded BearingFiring Pin Channel Liner