This is the Great Planes ElectriFly RimFire .55 42-60-480 Brushless Outrunner Electric Motor. FEATURES: For Sport airplanes up to 9.5lbs (4310g) and 3D airplanes up to 6lbs (2720g) Designed for explosive acceleration and maximum torque eliminating the need for a gearbox Lightened aluminum can houses high torque rare earth Neodymium magnets Double shielded bearings Virtually maintenance-free; no commutators or brushes to wear out Two year quality guarantee INCLUDES: Great Planes ElectriFly RimFire .55 42-60-480 Brushless Outrunner Electric Motor Outrunner Motor Mount GPMG1205 Outrunner Prop Adapter GPMQ4906 REQUIRES: Brushless Motor-compatible 60A Electronic Speed Control Propeller: Depending on aircraft application SPECS: Motor Diameter: 1.7" (42mm) Motor Length: 2.4" (60mm) Shaft Diameter: .20" (5mm) Shaft Length: .67" (17mm) Lead Length: 3" (76mm) Connectors: Bullet type, 4.0mm diameter Max. Constant Current: 45A Max. Surge Current: 80A Max. Constant Watts: 830W Burst Watts: 1850W No Load Current: 1.5A Input Voltage: 18.5-22.2V (5-6S LiPo) RPM/V (kV Rating): 480 Weight: 9.5oz (268g) Suggested Propeller Size: 13x10E - 15x8E COMMENTS: The three-number designation refers to Motor Diameter, Motor Length and kV Rating. jxs 4/20/06 ir/jxs upd OA 1/28/08 update JAW 7/10/09