This insert is designed to be used with a standard Right Handed EVG (Enhanced Vertical Grip) for shooters who want the Thumb Notch and Trigger Finger support on the left side of the grip surface. This 3D printed component will attach to your chassis via 2 oblong bosses on the insert plus double sided 3M PSA adhesive. Very simple, quick and easy to install. Masterpiece Arms EVH Left Hand Insert EVGINSERT-LH