A lowerator is a heated cabinet with a plinth fitted inside which is attached to a series of springs, The amount and size of the springs balances the weight of the china plates being warmed. Warmed plates are taken from the top of the stack, The stack rises giving you convenient plate access on demand. A heating element is situated under the stack of plates which heats the plates.
More expensive Hupfer lowerators we hire have a thermostat which ensures your plates are warmed to an optimum temperature. With cheaper lowerators you have to manage the temperature the plates achieve. The very bottom plates nearest the heating element reach higher temperatures, so always fill with extra plates as the very bottom plates can be very hot..