KKmoon New Arrival 4Pcs Emax Simonk 30A Brushless ESC Electronic Speed Controller for DJI DJI Flame Wheel F450 F500 F550 Multicopter Quadcopter ESC Simonk programe, perfect drive Low voltage, over heat protection, with power on self detection function MCU and BEC with independant regulator, high anti-interference ability Throttle stroke adjustable, compatiable with different receivers, good low speed performance Max. rotation speed support: 210,000rpm(2-pole), 70,000rpm(6-pole), 35,000rpm(12-pole)