This is the Hitec HS-425BB Deluxe Ball-Bearing Universal Servo.  This servo has a universal servo connector, so it will work with all current JR, Hitec, Futaba, and Airtronics Z radio systems.

HS-425BB is offered with dual ball bearings, impact resin gears, and high performance circuitry. As one of Hitec's longest running production servos, it has proven to be a durable and dependable servo year after year.

FEATURES:

• Dual Ball Bearings
• 3-Pole Motor
• Indirect Drive
• Plastic Gears

INCLUDES:
One HS-425BBS Servo
One Servo Accessory Bag (grommets, screws, bushings, horns)

SPECS:
Length: 1.59"
Width:  0.77"
Height: 1.44"
Weight: 1.60oz
Transit Time: 0.21 / 0.16 sec @ 60 deg.
Torque: 45.93 / 56.93 oz.in (4.8v/6v)