Lion Gears BridgeMount Tactical Extended Long Rail Cantilever Mount 0.75" Riser with 27 Slots BM2707EX Extended Long Rails for Multi Items Mounting Soluction. Perfect to Mount Dot Sight with Magnifier Purpose. .75" high, 11.75" long, 27 slots with 5.75" overhang, 80mm Mounting Slots Spacing Robust Built with Aircraft Aluminium and Steel to Steel Locking Screw & Nuts Modular Design with Under Bridge Space for Mounting Additional Accessories Light Weight Slim Design at 4oz