This is a Reef RC 422HDV2 High Voltage, High Torque Titanium Gear Digital Servo.

Features:
Specifications:
Submarine Waterproof: 7 Point Seals
Voltage: 4.8V - 8.4V 
Internal: Steel Gears / All CNC Aluminum Casing 
Bearing Type: 3 Ball Bearings 
Weight: 2.85oz 
Dimension: 1.57x.78x1.5 (LWH) 
Torque: 360oz @ 6.0V / 400oz @ 7.4V / 434oz @ 8.4V 
Speed: .138sec @ 6.0V / .11sec @ 7.4V / .10sec @ 8.4V 
Spline: 25T 
Dead Band Width: 2us