This U.S. made Flip-up Sight is a quality, low profile designed unit machined from 7075 Aluminum with steel parts. For use as a primary or back-up iron sight (BUIS)for installation on any AR15 / M16 Picatinny Receiver Rail, it clamps securely with a socket head screw from the left side and a locking plate on the right side. The aluminum sight base is Mil. Spec Hard Coat Anodized, and steel parts are Black Salt Bath Nitride Coated for superior corrosion and wear resistance. The sight can be deployed by simply flipping it up to its locked position. A left side push button will unlock the sight and foldit down repeatedly with no loss of zero. Height above rail when folded is .520″. A dual aperture system offers quick target acquisition with the larger “ghost ring” aperture, or long distance accuracy with the finer “peep” aperture. .5 MOA windage adjustments are made via a coin sized slot in the right side adjusting wheel.