Pixnor 30A Brushless ESC Speed Controller for Multicopter RC Helicopter Quad-Rotor Material: Durable plastic and copper wire. Size: about 45 * 24 * 11mm. Output: Continuous 30A, Burst 40A up to 10 Secs. Input Voltage: 2-3cells lithium battery or 5-9 cells NiCdNIMh battery. BEC: 1A 5V (Linear mode). Max Speed: 210,000rpm for 2 Poles BLM, 70,000rpm for 6 poles BLM, 35,000rpm for 12 poles BLM (BLM: BrushLess Motor). Compatible with: 400-450 helicopters Aircraft or Quad-Rotor Multi RC Helicopter.