dophee Dual Cantilever Ring Mount - QD Quick Release Rail Mount for Scopes & Optics - 30mm/25.4mm 1" A solid and heavy duty offset ring mount to install magnified optics scope for easier eye relief setup. Very helpful when mounting a scope with longer eyepiece tube, especially ones with illuminated reticles. Durable aircraft grade aluminum construction. Ring Width: 25mm. Ring Inner Size: 30mm (without insert). Ring Inner Diameter (with Insert): 25.4mm. Height: 62mm. Rail Size: 20mm. Length between two ring: 44mm. Overall Length: 134mm.