Geissele Automatics 05190B: The Geissele Super Modular HK 416 rail was designed to replace the standard rail on the HK 416 weapon platform. Constructed of precision machined, 6061-T6 aluminum allows the SMR HK to incorporate strength, rigidity and modularity while utilizing the stock HK barrel nut. Finished in Type 3 Hardcoat Anodize to meet military specifications and able to use rail sections at the 3, 6 and 9 oclock positions to mount accessory rails, using steel inserts for a rock solid, steel to steel connection; the SMR HK is trusted by our Nations elite warfighters, whose direct input and feedback allowed us to develop the feature and performance rich SMR 416.