Our Silver Frame filters are made from a single piece of roll-formed galvanized steel fastened together at one corner with a single rivet. This frame type is more cost-effective than the gold frame, but is not quite as strong and sturdy. Silver Frame filters are available in either 1/2″, 1″ or 2″ depths. The 1/2″ (7/16″ Actual) silver rigid framed filters have 2 layers of polypropylene between 2 layers of expanded steel for improved air flow and rigidity. Our 2″ rigid framed filters are configured with the same construction as the 1″ Electra silver, but with a 1.5″ white polyester ultra high loft impingement filtering center layer.