This is an exceptional K&D "Ajax" bi-polar dynamo electric motor. It has a hardwood base and a bi-polar field magnet wound for 2 to 6 volts. The commutator has a spring loaded copper "strip" brush assembly. The hardwood base is 3.75 inches by 2.5 inches and 0.5 inches thick. The motor and base stands 3.25 inches high.