Weaver Detachable Top Mount Extension Rings Weaver Top-Mount Rings offer wide top steel caps that hold zero under the most jarring recoil Loosen the thumb nuts and you can go back to iron sights in seconds Later you can put the rings back on the base, tighten the thumb nuts and the scope will be very clo Specifications: - Ring Diameter: 1" - Height: High - Extended: One Extended - Material: Aluminum