Specification: Item Type: Brushless Motor ESC Material: Alloy + Electronic Components Optional Type: A2217 1100KV, A2217 1250KV, A2217 2300KV Current: 40A Output Capacity: Continuous current 40A, short current 55A (not less than 10 seconds) Power Input: 2-4 lithium batteries (not included) BEC Output: 5V@3A (Linear voltage regulator mode - linear mode) Maximum Speed: 210,000 RPM for 2-pole motor, 7,000 RPM for 6-pole motor, and 35,000 RPM for 12-pole motor Size: Approx. 68 x 25 x 8mm / 2.7 x 1 x 0.3in 2217 Motor: Size: Approx. 27.8 x 32mm / 1.1 x 1.3in Weight: 68 g / 2.4 oz(approx.) Axle Diameter: Approx. 4mm / 0.16in Accessories: 4.0mm pillar adapter, motor mounting base, screws Props Recommended: 2217-1100KV: 11 or 10 inch props such as 1155, 1070, 1060, etc. 2217-1250KV: 9-inch prop such as 9050, 9045, 9060, etc. 2217-2300KV: 6 inch prop such as 6040, etc. Package List: 1 x Set of Motor 1 x Set of ESC Note: 1. Please allow 0.5‑2mm error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. Protection Function: The RC brushless motor with protection function, no matter where the throttle is, the motor will not rotates when connected to the battery. Throttle Calibration Function: Throttle calibration function about RC remote control drone, the throttle range can be calibrated to be compatible with different transmitters. Convenient to Operate: User programmable. Support a variety of program methods: emitting rod, LED program card. Very easy to operate at home or on the fly. This device will meet your different needs. Compatible with: The RC accessory kit is compatible with lithium and nickel metal hydride batteries. You can change the time to suit different brushless motors. Wonderful Replacement: The RC electric speed controller is a wonderful replacement for the old or broken one, directly fitment. This product with full protection such as low voltage cut off protection / overheat protection / throttle signal loss protection.