This is the Savox SB-2270SG "Monster Torque" Brushless, Steel Gear, High Voltage, Digital Servo.
Combines leading edge technology with super high 12 bit (4096) resolution and unique steel gears. Super light-weight. Brushless motor provides extremely high speed, incredible efficiency, and 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. Totally green – from materials to production, these servos are environmentally friendly. Ideal for rock crawlers, monster trucks and buggies, as well as every control surface for giant scale aircraft.