Parts Kit, AR15, Enhanced Field Repair. Don't get stuck waiting for parts. Grab an Enhanced Field Repair kit to have the most essential replacement pieces on hand. Includes: Firing Pin Hammer Spring Trigger Spring (2) Hammer/Trigger Pins Firing Pin Retaining Pin Extractor Extractor Spring and Buffer Extractor Pin Ejector (2) Ejector/Safety Selector Springs Disconnect Spring Ejector Roll Pin