These are vintage, unused items that were not tested, but very clean.  Silent buttons depress with proper resistance and battery compartments are clean and seem to confirm that these units are unused.  Perfect for a restore project in which code requires smoke detectors.  White mesh and gold ring, as well as back plate are metal. Black ribs on side appear to be plastic.  Requires (1) 9 bolt battery each, which is not included in sale.  Made in USA.  Please see pics for further description and condition.