Kaw Valley Precision Stainless Steel Heavy Tungsten Buffer 10 oz Small. 40 S&W .45 ACP and 10mm are a blast to shoot but can be tough on AR-15's internal components....Add a suppressor and the increased back pressure can cause tremendous damage without properly tuning ytheir blowback system. The KVP 10 oz tungsten blowback buffer helps tame the destructive forces in suppressed and standard blowback AR15's. Do yourself a favor and fine tune ytheir setup for the softest shooting PCC possible Specifications for Kaw Valley Precision Stainless Steel Heavy Tungsten Buffer: Manufacturer: Kaw Valley Precision Color: Stainless Steel Fabric/Material: Stainless Steel Gun Make: AR Platform Gun Model: AR-15 Gas System Length: Carbine Length Length: 4.125 in Weight: 10 oz Projectile Caliber: .355 Caliber .40 Caliber Caliber: 9mm Luger 10mm Auto Features of Kaw Valley Precision Stainless Steel Heavy Tungsten Buffer Increases AR-15's dwell time in blowback setups Quiets action (better for suppression) - 10.3-10.5 oz actual weight (tungsten weights can vary slightly) - 4 1/8 OAL (Buffer spacer is NOT required) Increases Reciprocating mass and weapon reliability Reduces wear on critical internal parts Reduces felt recoil Designed only for Carbine Length Stock and pistol kits Package Contents: Kaw Valley Precision Stainless Steel Heavy Tungsten Buffer What firearm models does the manufacturer say Kaw Valley Precision Stainless Steel Heavy Tungsten Buffer is compatible with? The manufacturer says that Kaw Valley Precision Stainless Steel Heavy Tungsten Buffer is compatible with AR-15Kaw Valley Precision KVP-10oz: Stainless Steel Heavy Tungsten Buffer 10 oz Small