Windham Weaponry 

 KIT BOLT REBUILD

If you've put a lot of rounds down-range, this is the Kit you need to rebuild the all-critical Bolt. The Kit includes the Extractor, its Pin, Spring, Black Neoprene Insert and O-ring, the Ejector, its Spring and Spring Pin, and a Set of 3 Gas Rings - all the parts necessary to bring a Bolt back to function like new.