This is the Futaba S3170G Digital Planetary Gear Retract Servo.
FEATURES:
For up to .60 size airplanes with mechanical retracts
Metal planetary gears and dual bearings
SPECS:
Torque: 7.0 kg-cm @ 4.8V (8.5 kg-cm) @ 6.0V
Speed: 0.57 sec/60° @ 4.8V (0.47 sec/60° @ 6.0V)
Size: 35 x 16 x 26mm
Weight: 26g
Rotation: 180°