Luth-AR Triple Tungsten H3-Buffer Carbine. You may also experience a reduction in felt recoil. The H3 contains 3 tungsten slugs in the buffer for a total weight of 5.40 oz or .35 lbs. Specifications for Luth-AR Triple Tungsten H3-Buffer: Manufacturer: Luth-AR Fabric/Material: Steel Gun Make: AR Platform Gun Model: AR-15 Weight: 5.5 oz Additional Features: Triple Tungsten Gun Type: Carbine Caliber: 5.56x45mm NATO .223 Remington Height: 3 in Package Contents: Luth-AR Triple Tungsten H3-Buffer What firearm models does the manufacturer say Luth-AR Triple Tungsten H3-Buffer is compatible with? The manufacturer says that Luth-AR Triple Tungsten H3-Buffer is compatible with AR-15Luth-AR CS-T3: Triple Tungsten H3-Buffer Carbine