This is the Savox SA-2271SG Ultra Torque Brushless Steel Gear Digital Servo.

Features:

• Combines leading edge technology with super high 12 bit (4096) resolution and unique steel gears.
• Super light-weight.
• Brushless motor provides high speed and torque, incredible efficiency, and amazingly low power consumption.
• Extremely strong unique steel gears ensure long-life and durability.
• The full aluminum case design not only looks good but also allows for cooler and smoother operating temps.
• Our servos are totally green – from materials to production, these servos are environmentally friendly.
• Ideal for rock crawlers, monster trucks, every control surface for giant scale aircraft, and 700 class heli cyclic.

Dimensions(mm): 40.3x20.2x38.5
Weight(g): 69.0
Speed(@4.8V sec/60): .105
Torque(@4.8V oz-in): 152.8
Speed(@6.0V sec/60): .085
Torque(@6.0V oz-in): 208.3
Speed(@7.4V sec/60): .065
Torque(@7.4V oz-in): 277.0
Gear: Unique Steel
Bearing: 2BB
Case: Full Aluminum
25 Tooth Spline