Designed to be a direct swap out for your 25 size glow engine. This brushless outrunner will provide more power and with its high efficiency, long run times.A quality motor, built specifically for planes designed to fly with a 25 sizeglow engine.Spec.Battery:3~4 Cell /11.1~14.8VRPM: 870kvMax current: 32A No load current: 10V/2.4ACurrent capacity: 44A/15secInternal resistance: 0.03 ohmWeight: 193g(not including connectors)Diameter of shaft: 5mmDimensions: 78x35mmRequired;50AESC3S~4S Li-Po/ 10~ 14-cell Ni-MH/Ni-Cd11x8 ~ 14x7 propSuitable for sport and scale airplanes weighing 3 to5.5 pounds (1.42.5kg).