These guidelines cover the 30mm and the 1″ Tube diameters:
On a Standard Rifle Contour the Medium rings will carry up to a 50mm objective. The High will carry up to a 56mm objective.
On a muzzleloader / Full Bull barrel, the Medium will carry a 44mm objective. The high will carry 50mm objective.
Solid Aluminium / One Piece Design.
Made In the U.S.A