rocky mountain goods floor register 4x12(duct opening measurements) - heavy duty walkable register - premium finish - easy adjust air supply lever - 4 inch by 12 inch floor vent (white) rocky mountain radar rocky mountain goods floor register 4x12 white is a premium finish floor register perfect for the 4 x 12 inch hvac. the heavy duty construction design allows for walk on use. made with a premium finish this floor register is paint chip and scratch resistant keeping the register looking brand new. for changing air flow, the easy adjust air supply lever allows for quick opening and closing of the air or heating vent. rocky mountain goods floor register 4” by 12” comes with a lifetime warranty.