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