It is a foil or metal label carrying both the model number and the serial number, and on every Maytag it is somewhere you have to open a door to see. Under the lid on a top-load washer; inside the door opening on a front-load washer or a dryer; on the inside wall of the fresh food compartment near the crisper on a refrigerator; on the frame behind the storage drawer on a range; on the edge of the door on a dishwasher, readable only when it is open.
Photograph it rather than copying it out. Model numbers on this badge run to ten or eleven characters with a color letter on the end, and a digit misread from a plate behind a laundry basket sends everybody looking at the wrong machine.