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 for smooth performance
INCLUDES: Futaba S3170G Digital Planetary Gear Retract Servo with universal connector

REQUIRES: Installing in airplane, connecting retract linkage and connecting to receiver
SPECS:    Torque: 94 oz-in (7.0 kg-cm) @ 4.8V
118 oz-in (8.5 kg-cm) @ 6.0V
Speed: 0.57 sec/60° @ 4.8V
0.47 sec/60° @ 6.0V
Size: 1.4 x .6 x 1.0" (35 x 16 x 26mm)
Weight: 0.9oz (26g)
Rotation: 180°