Tiger Rock .750 Low Profile Micro Gas Block and Sliver Carbine Length Gas Tube Assembled. 750 Low Profile Micro Gas Block and Sliver Carbine Length Gas Tube Assembled (GTC-B GB01-B) are designed to fit the AR Modern Sporting AR (M&P) and were made with the same manufacturing techniques as the AR. Once installed the .750 Low Profile Micro Gas Block and Sliver Carbine Length Gas Tube provide concentricity and therefore usually results in a stronger "better" seal around the locking lug. This is a common feature on the market that will be found on products from Tiger Rock. Due to the unique manufacturing process Tiger Rock .750 Low Profile Micro Gas Blocks and Sliver Carbine Length Gas Tubes will most likely be used in one build. Package Contents: Tiger Rock .750 Low Profile Micro Gas Block and Sliver Carbine Length Gas Tube Assembled (GTC-B GB01-B) Tiger Rock GTCBGB: .750 Low Profile Micro Gas Block and Sliver Carbine Length Gas Tube - Assembled (GTC-B GB01-B)