This is the Savox SB-2271SG "High Speed" 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.

Specifications:

• Dimensions: 40.3x20.2x38.5mm
• Weight: 69.0g
• Speed:
  • @ 4.8V: .10 sec/60
  • @ 6.0V: .08 sec/60
  • @ 7.4V: .06 sec/60
• Torque:
  • @ 6.0V: 15kg
  • @ 7.4V: 20kg
• Gear: Unique Steel
• Bearing: 2BB
• Case: Full Aluminum
• Output Shaft: 25 Tooth Spline