The BRN-PROTO, based on the original AR15 design, complete with trigger style charging handle, prototype style front sight and 25 round straight magazines Next up, the Brownell's 4x Retro Optic, sourced from the original vendor in Japan. Mounts to the carry handle. I just might have to get one for my upcoming GAU-5/U build Finally and most surprisingly, the BRN-180 upper. It's an upper that uses AR type action that fits on an AR lower. Want to be able to shoot your AR with the stock folded? Now you can! Boys and girls, The Good Ol' Days are now and they just keep getting better!