|The Provectus Quad Rail offers a larger inside diameter designed to accommodate your suppressor or for those that like the feel of a full sized quad rail. At 1.8” inside diameter your suppressor easily fits inside and the cutouts on the rail aid in rapid cooling. The Provectus Rail System features anti-rotation tabs, built in non-rotating QD sling mounts, scalloped rails that allow you to run without rail covers, hard anodize coating and super looks. The Provectus is available 0nly in 9”(13.1oz). Installation is a breeze using the standard USGI barrel nut wrench and ships with all mounting hardware.