Futaba S9157 Digital Hi-Torque Servo 富他巴  [S9157]

This is actually the Futaba S9157 High Torque Servo.

FEATURES:
Ideal for large competition airplanes
Coreless motor
Dual ball bearings and steel gears
Metal center case helps dissipate temperature for cooler operation
Twelve months limited guarantee

INCLUDES:
Futaba S9157 tall Torque Servo with 0.83" (21mm) diameter round horn, 1.8" (45mm) diameter round horn, 1.2" (31.5mm) 6 point horn, 1.5" (38.5mm) 4 point horn and mounting hardware

NEEDS:
Installing in model, linking linkage and linking to receiver

SPECS:
Torque: 425oz-in (30.6kg/cm) @ 6V
Speed: 0.14 @ 6V
Size: 1.6 x 0.8 x 1.5" (41 x 21 x 37mm)
Weight 2.5oz (71g)
Horn Screw Size: 3x8mm

COMMENTS:
Usage with NiCD batteries only
A note on Coreless motors: mainstream servo motors have actually a steel core armature covered with wire that spins inside the magnets. In a Coreless design, the armature makes use of a slim cable mesh that types a cup that spins across the beyond the magnet eliminating the hefty steel core. This design leads to smoother operation and faster response time.