The Super Modular Rail (SMR) MK4 M-LOK is Geisseles ultra-rugged M-LOK option. These rails are purpose-built and feature integrated M1913 picatinny rail sections at the fore of the rail in the 3 6 and 9 oclock positions. Maximum venting for heat dissipation also dramatically reduces the rail’s overall weight while maintaining its same strong and rigid platform. Utilizing Magpul’s M-LOK technology at the 3 6 and 9 o’clock positions as well as the upper 45 quadrants.