The Dye NT Complete Repair Kit includes every necessary part needed to fix and tune up your Dye NT Paintball gun. It is a Dye Certified repair kit so all the parts that are in this kit are the factory replacement parts used in the NT paintball marker. This will guarantee you have the correct O rings and parts to make your gun function properly. Aftermarket kits do NOT have the same parts and are not certified by Dye. If you want to ensure you have the correct parts that were specifically designed and tested in the Dye NT then ONLY buy the factory repair kit. These kits also come with color coded O rings so it makes changing any O ring on the gun very easy!