This HK 91 Rifle Length Keymod Handguard Rail is a sleek streamlined design is an ultra low profile handguard with generous mounting space to accept all KeyMod accessories. Rifle Length Handguard Has Superior ergonomics and simple, drop-in installation makes this the best HK pattern rail on the market. Fits most Mil-Spec HK 91 Rifle Length length models and variants. Black Anodized 6061 T6 aluminum. Accepts all standard Keymod Weaver/Picatinny 1913 rail accessories. Approximately 11.75 inches long.