This is the .05 OMA-3805-1200 Brushless Electric Motor from O.S. Motors. FEATURES: For .05 size airplanes Stainless steel prop shaft Rigid rear mounting design Two year limited warranty through Hobby Services beginning at date of purchase INCLUDES: .05 Brushless Electric Motor with Backplate, 3.5mm Gold Plated Male Plugs attached to leads, Three 3.5mm Female Plugs with Shrink Wrap, and Instruction Sheet REQUIRES: 20 - 40A Brushless ESC Slow flyer type electric propeller from 9x6 to 11x7 in size depending on specific aircraft SPECS: Rated Power: 250W Rated Voltage: 11.1mm Rated Current: 20A Maximum Current (5 sec): 30A No Load Current: 1.1A Phase Resistance: 65.1 miliohms Maximum Efficiency: 80% kV: 1200 Turns: 22 Poles: 14 Shaft Diameter: 0.16" (4mm) Shaft Length: 0.46" (11.7mm) Weight: 2.7oz (76g) Lead Wire Length: 1.96" (50mm) Lead Wire Gauge: 17AWG Length of Motor Can: 1.1" (27.5mm) Diameter of Motor Can: 1.45" (37mm) Prop Washer Diameter: 0.75" (19mm) Thickness of Motor Mount: 0.118" (3mm) Width of Motor Mount: 1.96" (50mm) Height of Motor Mount: 1.96" (50mm) COMMENTS: Nomenclature is defined as follows: 0MA means 0.S. airplane motor First two digits are the rotor diameter Second two digits are the length of the magnets Last digits indicate the kV of the motor jxs 11/14/12 ir/jxs