The motor features a 3.17mm hardened steel shaft, dual ball bearings, and has 3.5mm gold spring male connectors already soldered, and also includes 3 female connectors for your speed control. A bullet type prop adapter and cross motor mount are included in the package. Mounting holes have 16mm and 19mm spacing on centers and are tapped for 3mm (M3) screws.We recommend the following setup for the motor:3S LiPo setup for warbird, scale models and trainers:3S LiPo, 1000-2800mAh according to aircraft weight,25 or 30A ESC,8x4 propeller.2S LiPo setup for 3D airplanes and trainers:2S LiPo, 1000-1800mAh according to aircraft weight,25 or 30A ESC,9x4.7 propeller.Specifications:Number of Cells: 2-3s lipo; 6-10 cell NiMhMax Efficiency Current: 6-12A (>75%)No Load Current (10v): .7AMax Current: 16A/60sMax Efficiency: 78%Internal Resistance: 65mOShaft Size: 3.17mmPoles: 14Max Watts: 180wWeight: 47gDimensions: 27.5Packing List1 x Motor1 x Mounting bracket1 x Propeller adapter4 x Screws