Fortis Manufacturing, Inc. Billet Dust Cover, Fits AR-15, Red AR15DstCvr-CF-RED The Fortis Billet Dust Cover is manufactured from a solid piece of aircraft grade aluminum. This ensures overall durability and reliability vs other polymer versions. Easy to install and upgrade your existing ejection port dust cover on your .223/556 compatible builds. Will fit into mil-spec AR15 uppers and will quickly upgrade the form and function of your AR15.