The Missouri Tactical Products Grip Inserts are compatible with standard elongated M-LOK slots. They are 4.75 inches long and they can be cut to length depending on your need. They provide protection to your hand from abrasion at the same time giving you a very comfortable tactile feel. Grip Slot Inserts are made out of heat resistant silicone (up to 400F) for longevity and durability. They come packaged in sets of 5 pieces.