This is a Magpul Industries Accessory known as the XTM Enhanced Rail Panel, model MAG510-GRY.
The XTM Enhanced Rail Panels are low-profile" two-piece covers that attach anywhere on a 1913 Picatinny rail without having to remove previously mounted accessories. Replacing the original XTM Panels" The Enhanced XTM Panels feature an aggressive anti-slip texture and dual-side routing clips for retention of light/laser cables. The design and reinforced material construction ensure the panels will remain in place under all operating conditions" but allows for easy removal using the tips of two rounds when necessary. Each set comes with four (4) two-piece panels which will cover ONE side of a carbine rail. Made in U.S.A.
Features:
Low-profile, two-piece covers
Attach anywhere on a 1913 Picatinny rail
Panels feature an aggressive anti-slip texture
(4) two-piece panels
