Caliber: .300BLK Sound Reduction: 30 dB Length: 6.25'' Diameter: 1.5'' Materials: Stainless Mount: 5/8*24 Direct Thread Only Includes: (1) GT300K Suppressor The GT300K was designed using stainless steel as a more budget conscious offering to those looking to suppress .300blk. It is full auto rated and utilizes a patented retention system that will keep the can from backing off your threads. Sound reduction: 30 dB