This is the Savox SB-2272SG "Lightning 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 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 1/10 trucks and buggies, as well as every control surface for giant scale aircraft and 700 class heli rudder applications.

Specifications:

• Dimensions: 40.3x20.2x38.7mm
• Weight: 66g
• Speed:
• @ 4.8V: .05 sec/60
• @ 6.0V: .045 sec/60
• @ 7.4V: .032 sec/60
  
• Torque:
• @ 4.8V: 41.7 oz-in
• @ 6.0V: 69.4 oz-in
• @ 7.4V: 97.2 oz-in
  
• Gear: Steel
• Bearing: 2BB
• Case: Full Aluminum
• Output Shaft: 25 Tooth Spline