Includes one-piece bolt carrier upgrade and hand guards.

The Adams Arms AR-15 piston conversion kit is a high quality and user installable piston kit for the AR-15. The kit includes all of the parts needed to convert an AR-15 rifle from a gas driven system to piston system. The piston system eliminates the need to drive hot and dirty gasses back into the action of the rifle in order to cycle it. It also helps reduce felt recoil which leads to quicker second shot recovery time.

These are very nice and easy to install kits. Adams Arms offers a 30 day satisfaction guarantee and a lifetime warranty on the kit. They have lots of resources to help you learn about installation, benefits, fit with hand guards, and other information here:

Watch the Installation Video On YouTube