Aimpoint 12234 Twist Mount Ring and Base This Aimpoint Ring and Base complete include two pieces that allow rapid transition from 1x to 3x. The Aimpoint Twist Mount's base stays on the rail. This red dot sight accessory boasts the same Aimpoint quality as we have come to expect from Aimpoint Red Dot Sights. Features:- This Aimpoint Red Dot Sight Accessory is made to work with Aimpoint Red Dot Scopes Specifications:- Made of precision, anodized aluminum and steel construction- Fits all Picatinny rail rifles- Satin Black Ring and Base.