The latest edition of the BLS-H51B is bringing several improvements to inlcude upgraded bearing and drivetrain as well as increased torque and speed. The BLS-H51B V2 is everything you would expect from Blue Bird Servo. Monster Torque, Fast and buttery smooth. This high-voltage beast will not disapoint.
 
Helical Gears for supreme strength and precision.
 
Soft Start Protection
Over Voltage Protection
Low Voltage Protection
Locked Rotor Protection 
Temperature Protection
Includes Aluminum Servo Arm
 
Applications
Awesome for 3D Airplane, Jet & 1/5 or 1/8th Monster / Crawler / Off-road
Car.
 
Specifications 
Torque At 6.0V
  46.2 kg-cm / 641.7 oz-in
Torque At 7.4V
  55.7 kg-cm / 773.6 oz-in
Torque At 8.4V
  62.9 kg-cm / 873.6 oz-in
Speed At 6.0V
  0.12 sec / 60°
Speed At 7.4V
  0.10 sec / 60°
Speed At 8.4V
  0.09 sec / 60°
 
 
Power Supply
Operating Voltage
Range
4.5V ~ 8.5V ( 4 ~ 6 Cell Ni-MH or 2S Li-Poly / 2S Li-Fe)
 
Control Specifications 
Control System
   Digital Controller / AD 12-Bits Resolution ( 4096 Steps )
   Frequency：333Hz / Neutral：1520us
Dead Band Width
   0.001ms ( Default：1us)
 
Mechanical Specifications
Ball Bearing
   Dual, Steel
Gear
   All Steel Alloy Metal Helical Gears
Outside Case
   Full One-Piece Aluminum CNC Casing
Motor
   High-Efficiency Japan Brushless Motor
Horn / Gear Spline
   25 Teeth ( Same as F-Type )