2 Pc Medium Profile 25.4mm/30mm Scope Rings Mount for Picatinny Rails! 25.4mm/30mm Scope Rings - Perfect for mounting most scopes that are in a 25.4mm/30mm scope tube. With Stop-Pin Design - One of the high rings has a stop pin at he bottom, which prevents the ring from sliding once set. 6061 Aluminum, Solid & Durable - Precision machining of aircraft-grade aluminum alloy, solid and sturdy construction. Rail Clamp Screws Design - With 2 mounting screws & 4 scope clamp screws per ring, It will hold the scope more securely than a single screw on both sides.