30mm rings Medium profile Picatinny base 4 hex screws/ring secure the scope Twist Lock base * Special tape inside the rings keeps your scope tight without excessive clamp pressure!* Made of aircraft-grade aluminum with a steel locking plate, these UTG Max Strength rings will hold your optics securely to your gun. The Twist Lock base is so easy to attach and remove that you can move the rings with your scope from one gun to another.