CISNO Barrel Mount 1'' Ring Rifle Scope Picatinny Rail Adapter For 12 Gauge Shot Gun (2) Scope mount for mounting standard 30mm or 1 inch(25.4 mm) tube rifle scopes 30mm to 1" ring adapters included Riser Mount for Rifles with Picatinny/Weaver Rail All heat treated steel and aluminum construction and Precise machining Will fit most 12 gauge magazine tube extensions and also directly to long scope tubes with a 1" tube