early 1920's vintage american industrial cast iron wall mount thermostat cover designed and manufactured by the national regulator co., 208 s. jefferson st., chicago, il. the original brass-plated finish remains largely intact. the original mercury thermometer with lightly incised brass metal scale remain intact. the mechanical innards were removed long ago. two available (the other contains a nickel-plated finish). measures 8 1/4 x 2 5/8 inches. priced individually.