UTG PRO M-LOK(R) 4-Slot Picatinny Rail Section, Black M-lok 4 slot Picatinny rail section fully Compatible with any m-lok mounting platform Optimal 0.37 inch saddle height profile for versatile attaching of accessories for a myriad of different modular applications Precision Machined from 6061-T6 aircraft grade aluminum alloy with matte black hard coat anodize