The XTM Enhanced Rail Panels cover from Magpul is a low-profile two-piece cover that can be attached anywhere on a 1913 Picatinny rail. A significant advantage is that you don't need to remove other accessories when attaching it.
It features a non-slip texture and double-sided guide clamps for attaching laser cables. The cover fits perfectly in place in all operating conditions, but can be easily removed if necessary. The set includes 4 two-piece panels that cover one side of the rail.