This is the Savox SB-2270SG "Monster Torque" Brushless, Steel Gear, High Voltage, Digital Servo.

Features:

• 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.