Futabe micro servo is ideal for small electric planes and helicopters. Futaba S3157 Digital High Speed/High Torque Micro Servo with universal connector. .71 x .79 (18mm x 20mm) 4 arm servo horn (pre-installed). 0.79 x 1.6 (20mm x 40mm) 4 arm servo horn. 0.79 (20mm) diameter round horn.
Installing in aircraft, connecting linkage and connecting to receiver