The NcSTAR AR 15 QR Weaver Mount/Cantilever Scope Mount is made to mount to any riflescope or red dot sight to your rifle in a number of different configurations. The NcSTAR QR Lever System makes mounting the NcSTAR MARCQ Weaver Mount to your flat top in a fast and easy manner. The mount rings are 30 mm with 1" inserts and the mount rear ring is on a dovetail so you can adjust the spacing for a customized fit. In addition, the rear ring is also removable so you can set up your Red Dot Sight to co-witness with your weapon iron sights. It is constructed of hard anodized aluminum with solid steel.