TufForce 30mm one Piece Offset Dual Ring, 22MM High Profile, RG-WOF30H22Overall Length 110 mm / 4.5" High Profile, 22mm / 0.87" , with big see-thru hole, overall 110 mm / 4.5" Weaver/Picatinny Base length 80mm / 3.25", Ring width 20mm / 0.79"; distance between two Rings 50 mm / 2" Top half cover with 4 Screws, Allen Wrench Included, two nuts clamp on Weaver rail base Bar for extra recoil resistance, to be inserted into the rail slot Two M5 Nuts to fix on rail Lightweight and Extra-Durable 6061 Aircraft Aluminum, Black