Evolution Gun Works Delrin Ring Inserts 1in.. They are designed to work with the 30mm scope rings by Evolution Gun Works allowing the rings to accommodate a 1" rifle scope tube. These Evolution Gun Works scope ring inserts are part of the Rifle Scope Mounts Rings and Bases selection available through our online store. Specifications for Evolution Gun Works Delrin Ring Inserts 1in.: Fits: EGW 30mm Tactical Scope Rings Features of Evolution Gun Works Delrin Ring Inserts 1in.: Reduces ring opening to 1 inch Machined polymer inserts Package Contents: Evolution Gun Works Delrin Ring Inserts 1in. EGW Scope Mount Ring Inserts 2708 - 1 inch