Rear flip-up sight is made of tough, metal-reinforced polymer with steel apertures for both light weight and durability. Sight snaps up into position instantly under robust spring pressure when the finger pad is depressed, and can be easily retracted to the folded position with one hand. Rear sight has flippable apertures, large for close-range shooting (0-100m) and small for longer-range applications (100-300m), with a notch at the top for quick CQB sighting or engaging targets at 500-600m range. Front sight available separately. Sights are designed to lean to the rear and should not obtain a vertical position when installed Mfg: A.R.M.S.,Inc SPECS: Reinforced polymer, matte black. Steel apertures, matte black. Sight is 5/8" high when folded, 1 3/4" total height when deployed. #71L-R Rear Sight 2 1/4" long, 1 1/4" wide.