1PC Back Spacer Signet Ring Upgrade For Spyderco Delica 4 Knives Feature: This is a unique and convenient addition to your for Spyderco cutter. Simply replacing the back gasket of the cutter with these precision-machined aluminum rings. Can greatly improve the ease of deployment and overall control. The internal 1" diameter of the signet ring fits most fingers and is easy to pull out of the pocket. Specification: Material: aluminum alloy fit for DELICA 4 Package included: 1*Signet Ring (The knife shown in our picture is not included)