Both are made from durable, metal-reinforced polymer and are a good option when seeking a quality sight. The apertures on the rear sight are real steel and not subject to distortion like thin plastic types. Both: .600a ^2 when in the folded position, from the top of the receiver. Both: 71 Front and Rear Sights are designed to allow attachment to all universal dovetail rails. Not for use on Dovetail Gas Blocks. 100% MADE IN THE USA.