Favourite 4Pcs 20A 2~4 LiPo Battery OPTO ESC Brushless Speed Controller for F450/550 Quadcopter Multicopter<br><br>Features:<br>Can be programmed by program card or transmitter<br>Based on BLHELI firmware, futher optimized to the perfect flying performance<br>Max speed: 210,000 RPM for 2 pole, 70,000RPM for 6 pole, 35,000 RPM for 12 Pole<br>Seperate power supply for MCU and BEC, enhancing the ability of eliminating magnetic interference<br><br>Specification:<br>Constant Current: 20A<br>Burst Current: 25A<br>Input Volt: 2S-4S LiPo battery<br>Suit for F450/550 Quadcopter Multicopter<br>Item size: 25 * 13 * 4mm (Without cable)<br>Item weight: 9g / Pc<br><br>Package Information:<br>Package size: 8 * 5.5 * 4cm / 3.2 * 2.2 * 1.6in<br>Package weight: 36g / 1.1oz<br>Adhesive tape package<br><br>Package List:<br>4 * Favourite 20A ESC