This universal starter (suitable mainly for model airplanes) consists of a high-torque electric motor equipped with a switch and an adapter with a rubber insert. To start the engine, press the adapter with the insert against the propeller cone (with a diameter of at least 38 mm). For starting engines using a V-belt in cars or boats, the adapters are usually equipped with a recess, or a plastic starting insert (“plate”) can be slid onto the adapter. To start engines with a small spinner or a duralumin spinner nut, the insert must be flipped over.