"Platinum-30A-OPTO-PRO" ESC is the best choice for multi-rotor aircraft.

1 Specification

1.1 Output: Continuous 30A, burst 40A up to 10 seconds.
1.2 Input Voltage: 2-6 cells lithium battery or 5-18 cells NiMH battery. 
1.3 BEC: Not available.
1.4 Refresh rate of the throttle signal: 50Hz to 432Hz.
1.5 Max Speed: 210000rpm for 2 Poles BLM, 70000rpm for 6 poles BLM, 35000rpm for 12 poles BLM.
(BLM = BrushLess Motor)
1.6 Size: 55mm (L) * 25mm (W) * 12mm (H).
1.7 Weight: 31g.

2 Features

2.1 High performance microprocessor, best compatibility with all kinds of motors, highest driving efficiency.
2.2 Optimized for multi-rotor aircraft. 
2.3 Smooth, linear, quick and precise throttle response.
2.4 Multiple protection features: Low-voltage cut-off protection / Over-heat protection / Throttle signal loss protection.
2.5 The firmware of the ESC can be updated through the built-in USB adapter in the Professional LCD Program Box.
2.6 User programmable. 
2.7 Multiple program methods supported: transmitter stick, Digital LED Program Card, Multifunction LCD Program Box, Professional LCD Program Box, PC software. Very easy to program the ESC at home or at the flying field.