The Propeller Belt is an invention of Professor Dweeb that allows him to lift off and fly around.
Professor Dweeb used the Propeller Belt to fly up to the Firehouse kitchen and sneak up on Slimer. However, several nails sprang loose and fatally damaged the propeller. Luckily, Dweeb prepared for such a contingency and activated a parachute. More nails shot out from the kitchen and popped the parachute, as well.