Most AR-15 noise reduction methods focus on muzzle, but the Armaspec Gen2 Sound Mitigation Buffer takes an entirely new approach by dealing with the clacking and scraping on the OTHER end of the rifle. Designed as a single-stage drop-in replacement for your AR-15's standard buffer and spring, the Gen2 SMB keeps the buffer spring from rubbing against the inner wall of the buffer tube-preventing a great deal of noise in the process. Spring weight is adjustable: the main spring can be trimmed at 4 ounces per coil to reduce tension, up to a max of 12 coils (3 lbs.). Anda |it reduces felt recoil too.The Sound Mitigation Buffer is made in America, backed by a lifetime manufacturer's warranty, and available in 5 different configurations to fit everything from standard AR-15 carbines to AR-style pistol-caliber carbines. If you want a smoother, softer-shooting AR-15, look no further. Details: Keeps the buffer spring from rubbing against the inner wall of the buffer tube Single-stage drop-in replacement for your standard buffer and spring Reduces felt recoil Adjustable spring weight via trimming coils; 4 ounces per coil, up to 12 coils Easy installation, no gunsmithing required Made in USA Includes polymer base guide rod, spring and bufferConfigurations: Carbine: 4.41 oz. Heavy: 4.91 oz. Heavy 2: 5.81 oz. Heavy 3: 6.71 oz. 9MM: 9.88 oz.