This kit includes a 2217 KV1250 motor, 8060 propeller, steering motor, and 40A XT60 ESC to boost your RC helicopter's performance. The SG90 9G micro servo weighs only 9g with a torque of 1.5‑1.7kg/cm (4.8V‑6V). The 40A ESC features a safety arming function, throttle calibration, and supports multiple programming methods. Compatible with lithium batteries (not included). Timing can be adjusted to suit different brushless motors. Comprehensive protection includes low-voltage cutoff protection, over-heat protection, and throttle signal loss protection. SG90 9g Servo Parameters: Size: Approx. 21.5 x 11.8 x 22.7 mm/0.85 x 0.46 x 0.89in Weight: Approx. 9g/0.32oz Idle Speed: 0.12s/ 60 degrees (4.8V) Stall Torque: 1.5-1.7kg/cm (4.8V-6V) Working Temperature: -30-+ 60℃ Dead Zone Setting: 5 microseconds Working Voltage: 4.8V-6V 2217 Motor Specifications: Size: Approx. 27.8 x 32 mm/1.1 x 1.3in Shaft Diameter: Approx. 4 mm/0.16in Kv: 1250kv 40A ESC Specifications: Connector: XT60 Continuous Current: 40A Peak Current: 55A (10S) Power Input: 2-4 lithium batteries (not included) BEC Output: 5V at 3A (linear regulator mode-linear mode) Maximum Speed: 210,000 RPM for 2-pole motor, 7000 RPM for 6-pole motor, 35,000 RPM for 12-pole motor Application: Suitable for RC remote control helicopter Includes: 1 x Motor, 2 x Propeller, 2 x Steering Motor, 1 x ESC (Battery not included), 1 x Motor Base, 1 x Conical Head, 6 x Servo Arm, 1 x Tie, 10 x Screw, 2 x Rows of Propeller Washers