JP Enterprises Silent Capture System is a self-contained buffer system that reduces recoil, smooths out the operation of the rifle, and gets rid of the cheese grater sound of the buffer and spring. These are one of the best upgrades we have found made to a rifle that you already own and a must if you are in the process of building one. Includes spacer to allow for installation in both carbine- and rifle-length buffer tubes. These work great even the higher pressure calibers if paired with an adjustable gas block.