The Geissele Super Modular Rail MK4 (SMR) was designed as an ultra light weight rail system for the M4 Carbine and all mil-spec AR-15 variants. The SMR MK4 was designed to do a good job in meeting design specifications for a good M4 weapon rail with an emphasis on weight reduction.
Features an ergonomic design, with a flexible and modular set up procedure. The free floating design is strong and rigid, and overall one of the lightest weight systems on the market. Accessory rails are easy to install, and do not require a backing plate. 13" in length, sand.