Mission First Tactical's Flip-Up Rear Back-Up Sight is constructed of military-grade polymer. It is windage adjustable, with infinite MOA (flat head screwdriver is required). The dual peep, same plane aperture allows for perfect co-witness, and a slim profile allows the sight to sit under most magnifiers and optics. The rear sight mounts onto a 1913 Picatinny rail. and works with all standard height front sights. Unlike other backup sights, MFT developed a shroud to shelter the aperture from debris and impact damage when not deployed. It weighs just .5 oz. It is 2.23 long, 1.08 wide, and is .879 high. This model has a black finish.