NcSTAR's 3rd Generation MAR4S, .223/5.56 Carbine Length Quad Rail Handguard. The 3rd Gen MAR4S is now lighter and has a slimmer profile than earlier models. Fits onto carbine length gas system using the GI Handguard Cap and Delta Ring The Solid Quad Rail provides the steady platform attaching: Optics, Lasers, Flashlights, Verticle Grip, Bipod, and other accessories. Large ventilation holes to help keep the barrel cool Very easy to install with four Allen head screws and the provided mounting tool. No gunsmithing required, drop-in fit. All Aluminum Construction. Black Anodized finish Laser engraved rail markings (white) Length: 6.5" (6.7" O.A.L.) Width: 2.3" Height: 2.3" Weight: 9.9 oz