This is the Futaba S9257 High Speed Digital Servo for Helicopter Gyro Operation.

FEATURES: For use with the Futaba GY401 (FUTM0807, FUTM0808) and the GY502 gyros
Equipped with two ball bearings

INCLUDES: Futaba S9257 High Speed Digital Servom with .83" (21mm)
diameter round horn, 1.5" (39mm) diameter four-point horn, 1.2" (32mm)
diameter six-point horn, mounting hardware, digital servo
precaution sheet and warranty card

REQUIRES: Connecting to gyro

SPECIFICATION:
Length: 1.40" (35.5mm)
Width: .59" (15mm) Height: 1.13" (28.6mm)
Weight: .9oz (26g)
Torque: 27.76 oz-in (2 kg-cm) at 4.8V
Operating Speed: .08 sec/60¡ã at 4.8V Cord Length: 7.9" (200mm)

COMMENTS: For use only with FM, PCM and HRS systems. Do not use with AM systems.