Precision Reflex MSTN Quiet Control Brake .308 Stailess Steel Silver. Specs: 304 Stainless .95in diameter x 2.05in long barrel thread is 5/8in - 24in. The lead diameter is .750 and the body of the brake is .950. The 3 holes should be at 1 O'clock from the shooter when in the tightened position. Tighten the brake using a round screwdriver in the slotted hole closest to the barrel. The brake comes with a packet of shims to set your timing. Specifications for Precision Reflex MSTN Quiet Control Brakes: Manufacturer: Precision Reflex Caliber: .308 Winchester Fabric/Material: 304 Stainless Steel Threads per Inch: 5/8x24 Gun Make: AR Platform Inner Diameter: 0.75 in Outer Diameter: 0.95 in Length: 2.05 in Package Contents: Precision Reflex MSTN Quiet Control Brakes Precision Reflex 03-0090: MSTN Quiet Control Brake .308 Stailess Steel Silver