A VERY NICE OLD WAGNER WARE PLATTER APRX 12 3/4" x 8 7/8" THAT READS ON THE BOTTOM - THE AL CARDER SIZZLING STEAK PLATTER, TRADE MARK REG-U.S. PAT OFFICE, PATENT PENDING, WAGNER WARE (SHARED W) SIDNEY O, AND THE NUMBER 340C. I AM NO METAL EXPERT, BUT TO ME, THIS SEEMS TO BE A HEAVY ALUMINUM. THE BOTTOM ALSO HAS 6 SMALL "FEET".  IT IS A BEAUTIFUL PIECE!!