Instead of sourcing every part individually the slide completion kit includes every part needed to assemble the internal workings of your slide all designed to work together. Includes: Striker (firing pin) Spring Extractor Striker (firing pin) Safety Spring Back Cover Plate Extractor Depressor Plunger RA Precision Striker (firing pin) Striker (firing pin) Spacer Sleeve Depressor Plunger Spring Striker (firing pin) Safety Spring Loaded Bearing Striker (firing pin) Spring Cups Slide Channel Liner. Tighter tolerances than factory Low-temperature vacuum PVD (Physical Vapor Deposition) coating on select parts creates a durable barrier against wear and tear Select parts CNC-machined from solid stainless steel billet Individually hand inspected for accuracy.