You are bidding on one new Airpax hydraulic magnetic circuit breaker, part number IEG66-36276-2-UV.  Part number 1690520-1 is also on the label.  This is a 2 pole 35 amp 250v rated circuit breaker.  The 4 mounting screw holes have #6-32 threads.  This item is also equivalent to Onan part number 320-2442-01.