one is a #6 - 6 inch and the other 9 inch from 2 different suppliers; one from brooklyn NY and the other from milwaukee Wi. but machined identically the same. I would go as far as saying they were made at the same facility. Since they did come from 2 different suppliers, I would surmise they were ordered at 2 different dates. The packaging fits each unit to a tee, but other than the suppliers name and addy there are no other identifying writings. The question is why would the end user want/need/or have to order from said suppliers instead of going straight to the manufacturer if they were custom made. These may be an off the shelf item - maybe?