The seller must not have stared at the pictures as long as we do/would, the model tag is quite visible with the door open/racks picture - right at the top left side of the tank. I would guess this is a WU-601 - it's one of the first of the belt driven pumps. Very nice machine, I would love to find the very first of these, with the direct drive pump offset from the sump area in the back, easily recognizeable by the SS figure "8" sump cover.