NcStar Ar15 Qr Weaver Mount/ Cantilever Scope Mount Rear Ring 30mm. 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 30mm with 1 inch 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. Constructed of hard anodized aluminum with solid steel.We offer complete line of NcSTAR Rifle Scope Mounts Rings and Bases. For our complete selection of products by NcSTAR on sale please visit our NcSTAR page. For more Rifle Scope Mounts Rings and Bases please visit our Rifle Scope Mounts Rings and Bases store section. Specifications for NcStar Ar15 Qr Weaver Mount/ Cantilever Scope Mount Rear Ring 30mm: Gun Model: AR15 Features of NC Star Ar15 Weaver Mount MARCQ: Ncstar warranty Made of Hard Anodized Aluminum Package Contents: Nc Star Ar15 Qr Weaver Mount MARCQ NcStar Ar15 Qr Weaver Mount/ Cantilever Scope Mount Rear Ring 30mm MARCQ