Mike, it's a 13.75" dia x 15" pitch 3 blade aluminum heavy load prop (Propco # LM57-15SP) usually used on heavier workboats or house barges. I also have a neat 4 blade alum from them (QRJ-T LM58-17SP) for better cruising speed (30 knots @ 5000 rpm instead of 25) if I'm not going to be doing any trolling and not loading the boat too heavy (it's a heavy boat to begin with).