Description: Safety arming feature: Regardless the throttle stick position, the motor will not spin after battery connected. Throttle calibration funtion: Throttle range can be calibrated to be compatible with different transmitters. User programmable. Multiple procedure methods supported: transmitter stick, LED procedure Card. Very easy to procedure the ESC at home or at the flying field. Compatible with Lipo and NiMH battery. Timing can be changed to be suitable for different brushless motors. Full protection: Low voltage cutoff protection / Over-heat protection / Throttle signal loss protection. Specification: Current:40A Power input: 2-4 lithium batteries(Not Included) BEC output: 5V@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 Size Chart: Size:approx.68x25x8mm/2.7x0.98x0.3inch Package Includes: 1 Piece brushless ESC(2 Pack) Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement, there may be 1-2cm error in size.