This is the Futaba S9402 Hi-Speed Coreless Ball Bearing High-Torque Servo.
Great for Cars, Boats, Airplanes and Helicopters.

This servo can produce high-current draw from your batteries.
If using NiMH or Li-Po batteries, make sure they are capable
of delivering sufficient Amps.

FEATURES: Hi-Torque
Coreless Motor
Two Ball Bearings
Metal Gears (brass and steel)
Dust and Water Resistant
Plated "J" type Connector (gold colored)
One-Year Warranty

SPECS: Size: W 0.8" (20mm) x L 1.6" (41mm) x H 1.5" (38mm)
Weight: 1.9 ounces (55 grams)
Torque: 89 oz/in @ 4.8V - 111 oz/in @ 6V
(6.4 kg/cm @ 4.8V - 8.0 kg/cm @ 6V)
Transit time: .13 sec/60 deg @ 4.8V - .10 sec/60 deg @ 6V
Connector: "J" type with about 10" lead

INCLUDES: One S9402 servo
Four black rubber rectangular grommets
Four brass eyelets
Four servo mounting self-tapping screws (#4x1/2")
Three black plastic servo horns (arms)
1- circular
1- "X"
1- "6-arm"