The new A.R.M.S. ? #71L series of Front and Rear Sights with STEEL APERTURES!!! They are designed to allow attachment to all Universal Dovetail 1913 and Weaver style Rails. Both are made from durable metal-reinforced polymer and are a good option when seeking a quality sight. Both are .600 when in the folded position from the top of the receiver. Not for Dovetail Gas Blocks.