BridgeMount(R) Slim 45 Degree Pro Mount BM03D45, 1.37" Length 3 Slots Low Profile Compact 45 Degree Angle Mount, Picatinny/Weaver Rail 1.37" Long Sufficient Clearance For Both Top and Side Mounting Space; Only 5mm Saddle Height, Perfect to Mount Under Scope or BridgeMount Risers Perfect Alignment with AR Barrel While Rotating 45 Angle Degree System Oriented Design to Build a Flexible and Compact Bridge Mount Systems when Use with Lion Gear's Bridge Mount Slim Design & Truly Light Weight with Robust Compact Steel Locking Bolt & Steel nut. Threaded into Steel, Not Aluminum, Free of Stripped Threads and No Bulky Screws and Knobs!