Welcome to Sidco  Your Leading Manufacturer of Industrial Air and Gas Filter Replacements CONSTRUCTION Panel filters are constructed of a heavy gauge galvanized steel frame. The media is bonded to this frame with high strength adhesive on all sides, which ensures the filters endurance in the application. 20 Gauge flattened expanded galvanized carbon steel is used to maintain strength within the flow. UNIQUE FEATURES Panel filters are built to original equipment specifications with full media capacity. They are a cost effective choice to OEM replacements.