This is a handy tune-up kit or backup parts kit for your Ruger 10/22. These two essential parts do most of the work every time a cartrige is fired. After extensive shooting, firing pins will eventually fail due to heavy wear on the point, fouling, and corrosion. The extractor point will also wear out and fail to grip the case rim for cartridge ejection. Misfiring, ejection problems, and feeding problems will result when one or both of these parts fail. Recommended for installation or by experienced hobbyists or gunsmith. This kit includes factory Parts B-11, B-14, & B-15. Detailed installation instructions are included as part of the kit.