10.5 Inch HK416 M-LOK rail from OMG for airsoft only. Barrel nut is AEG/MWS/PTW Spec. Minor damage to barrel nut from screw running into barrel nut during install attempt. (Long story short, tried to install on TM m4 Mws, not for m4. It's for a 416.) Will trade for a TM m4 MWS M-Lok rail or sell for 85-90 USD. Listed on JK Army for 115. Only tried to install once before realizing mistake. Not used since then. Free shipping.