Hawks Tech 11mm Dovetail - 20mm Weaver Rifle Scope Rail Adapter. Airgun to Weaver Converts 11mm rail to 20mm Weaver rail 3/8"Dovetail To 7/8"Weaver Mount Mount 20mm scopes/red dots to your 11m airgun rail Material: High Quality Aluminum Length: 3.9" .Weight: 2.3 oz