This is a Magpul Industries Rail Covers known as the M-LOK Rail Cover Type 1, model MAG602-GRY.
M-LOK Type 1 Rail Covers are low-profile and light weight covers that install directly onto M-LOK compatible systems. Made of an extremely heat resistant flexible material" these covers offer an enhanced gripping surface. At 9.5" in length they cover six full M-LOK slots but can be cut for customized length or to combine colors. Includes two Covers per package.
Features:
Compatible with all M-LOK systems
Enhanced gripping surface
Includes two Covers per package
Low profile and light weight
