The other reason that it could be built in under a counter is that it is the first design of the 29' combo, the one that used a centrifugal separator for the dryer lint so that it was washed down the drain during the next wash cycle instead of caught in a lint screen. It had no lint screen on top like other KM and WP combos. It has an access door in one perforated panel in the drum to access the wash filter which, in these machines, was in the sump of the outer tub. When that clogged, the machine would not drain and the user had to lift out the driping wet load and go fishing. It is also the model that had a spin speed of 500 rpm. The blower and pump ran throughout the entire cycle and there was a damper that recirculated most of the air during the wash portion of the cycle. During the final spin portion, the heater came on to preheat the clothes for the dry cycle. There were problems with lint clogging and WP retrofitted these machines in the field. They had new trannies so there would be a pulley for both the blower and the pump, the shifter solenoid to switch power from the pump to the blower when the dry portion started, the separate poly-v belt and, most importantly, they had to have new tops and blower housings to accommodate the lint screen for the dryer. People who had them installed under a counter were sol, but only the bol model without dispensers could be installed that way so maybe a whole lot of the retrofitted machines were not undercounter installations except in the cases where they were installed by builders.