Perfect for adding correct height for optics on your AR-15 or tactical rifle. With 5" of rail space, this mount brings the sight plane up by .83".Perfect for adding correct height for optics on your AR-15 or tactical rifle. With 5 inches of rail space, this mount brings the sight plane up by 0.83 inches. Features: Accepts all standard Weaver/Picatinny 1913 accessories Lifts your mounting surface by 1 inches Perfect for co-witnessing with BUIS