Midwest Industries Combat Rifle Fixed Front, HK Type, Mil-Spec Height, 6061 Aluminum, Black Finish MI-CFFS-HK If you prefer battle proven design or want a set of top quality back up irons" then the Midwest Industries HK Style Combat Fixed Front Sight fits the bill. Made of durable" yet lightweight aircraft grade aluminum" the sight is secured to any Picatinny" weaver top mounted rail along any sized handguard.