I have no clue what it is. It says gillette on the bottom of the head but I couldn't find any numbers. I worked on it with scrubbing bubbles and a scouring pad. It's still got some grime but nothing compared to what it had just a little in the grooves and a couple little spots in the head. I'll post more pictures when it's actualy finished. I threw a wilkinson sword blade in it and it shave like a dream. This will defiantly be my new in a hurry shaver.