This is the Futaba S9157 High Torque Servo.

FEATURES: Ideal for large competition airplanes
          Coreless motor
          Dual ball bearings and metal gears
          Metal middle case helps dissipate heat for cooler operation
          One year limited warranty

INCLUDES: Futaba S9157 High 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

REQUIRES: Installing in model, connecting linkage and connecting 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: Use with NiCD batteries only
          A note on Coreless motors: Conventional servo motors have a steel
            core armature wrapped with wire that spins inside the magnets. In
            a Coreless design, the armature uses a thin wire mesh that forms a
            cup that spins around the outside of the magnet eliminating the
            heavy steel core. This design results in smoother operation and
            faster response time.

                                                                   jxs 01/20/09
                                                                         ir/jxs