UL-approved WD 200 and Sprite 12 & 16 machines starting from serial number 0350 00001 is equipped with the new switch and the new cooling air cover. The new type of switch part number 140 8096 500. This switch Must be used in all machines produced after the above mentioned serial numbers. The old type of switch part number 140 8475 000. This switch must be used in all machines produced before the above mentioned serial numbers.