The MK12 Gas Block is only compatible with the RIS II (M4A1 & MK18) family of rail systems manufactured by Daniel Defense. It is not compatible with any other Daniel Defense rail system. This is due to various clearance issues. This only applies to rail system lengths that would completely shroud the gas block. If you are mounting the gas block to the barrel without being shrouded by the rail system, then this does not apply. In that case, it will fit as long as barrel diameter is .750.
- Hardened 416 Stainless Steel - Black Oxide Coated - Precision CNC Machined - Low profile gas block - 2 set screws - Gas tube roll pin - 0.5 ml. Loctite 262 Threadlocker
- Product Weight: 1.9 oz. - Inside Diameter: 0.750" - Attachment Style: Set Screws