The B5 Systems M-LOK Rail Covers provide better grip on your handguard and keep your hand protected from the heat generated after long strings of fire. They are made from heat resistant material and attach directly M-LOK slots.Features: Black Heat resistant material Textured M-LOK compatible Pack of 4 Covers 3 M-LOK slotsB5 Systems believes in building products that favor function over flash. Every component is thought out and tested to ensure every product functions as intended. If you are building a serious rifle that you want to be able to trust, you can't go wrong with B5 Systems.