FOSA EMAX ES9051 4.3g Digital Micro Servo Plastic Gear 0.8kg Torque Servo RC Parts for 3D F3P RC Airplane, for FUT/JR Plug

Best 250 gram drone servo. See attached video. No other servos can make a helicopter fly like that. And the helicopter flies for 35 minutes per flight thanks to a set of this light weight servo.