The Zaffiri Precision Slide Parts Kit is 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. Parts included: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 linerExtractorSlide cover plateRecoil spring assembly DISCLAIMER: This product is not manufactured, authorized, endorsed, or warranted by GLOCK. GLOCK does not warrant or represent that this product is compatible with GLOCK pistols.