This is a quality, U.S. made, low profile design Flip-up Sight of 7075 Aluminum and steel parts intended as a primary or back-up iron sight (BUIS) for installation on any same plane Picatinny Gas Block or accessory forend. A socket head screw from the left side clamps the right side locking plate to the Picatinny Rail for a secure mounting with no loss of zero. The sight can be deployed by simply flipping it up to its locked position. A left side push button will unlock the sight and fold it down. Height above rail when folded is .520″.The sight includes a standard A2 Front Sight Post, adjustable for elevation. The Post can be adjusted with any standard front sight adjusting tool, andis protected by machined aluminum ears on each side. This sight has passed a 10K Round Endurance Tested as well as a Salt Spray Environment Test. The aluminum sight base is Mil.Spec Hard Coat Anodized, and steel parts are Black Salt Bath Nitride Coated to provide superior corrosion and wear resistance.