Hobbypower 30a Brushless Speed Controller Esc Multicopter Kk Quadrotor(pack of 4pcs)
Compatible with: 400-450 helicopters / Aircraft or Quad-Rotor Multi RC HelicopterGood for quad-rotor KK multi-copterquantity:4 sets1.Specification1.1 Output: Continuous 30A, Burst 40A up to 10 Secs.1.2 Input Voltage: 2-4 cells lithium battery or 5-12 cells NiCd/NIMh  battery.1.3 BEC: 2A / 5V (Linear mode).1.4 Max Speed: 210,000rpm for 2 Poles BLM, 70,000rpm for 6 poles BLM,  35,000rpm for 12poles BLM.(BLM: BrushLess Motor)1.5 Size: 45mm (L) * 24mm (W) * 11mm (H).1.6 Weight: 25g.2 .Features2.1 Safety Arming Feature: Regardless the throttle stick position, the motor  will not spin after battery connected.2.2 Throttle Calibration: Throttle range can be configured to provide best  throttlelinearity, fully compatible with all market available transmitters.2.3 Programmable Items:Brake Setting: brake enabled / brake disabled.Battery Type: Li-xx(Li-ion or LiPo) / Ni-xx(NiMh or NiCd).Low Voltage Protection Mode(Cutoff Mode): Gradually reduce the output power / Cutoff the output power.Low Voltage Cutoff Protection Threshold (Cutoff Threshold): low / medium / high.Start Mode: normal / soft / very soft.Timing: low / medium / high.Reset: reset all the programmable items to their default settings.2.4 Full Protection Features: Low voltage cutoff protection / Over-heat  protection /Throttle signal lost