I have a slightly used 9" LWRC rail system. It is GTG on a DI gun and some piston guns. It is entirely free float and mounts to the standard barrel nut. Super easy installation. I got it used and used it for a little while, very nice lightweight rail system. I sold the upper without handguards and these have no home sooooo away they go. I would like to get $140 shipped for them. Email me if you want 'em. Sorry my pictures pretty much blow, only gots an iphone fer pick-cher takin'