This Yankee Hill 3 Inch Picatinny Forearm Rail System is constructed from aircraft quality aluminum and hard coated to Mil. Specs for durability and strength. This rail is 1/4 inch tall x 3 inches long and will accommodate your individual shooting needs. The Forearm Rail System is made in standard picatinny configuration and comes with mounting screws. This rail will co-witness with a flat top upper receiver.