This is the Savox SC-1258TG Super Speed Titanium Gear Digital Servo.

Features:

Combines leading edge technology with super high 12 bit (4096) resolution and titanium gears.
Super light-weight.
Coreless motor provides high speed, incredible efficiency, and low power consumption.
Extremely strong titanium gears ensure long-life and durability.
The aluminum case design not only looks good but also allows for cooler and smoother operating temps.
Our servos are totally green – from materials to production, these servos are environmentally friendly.
Ideal for CCPM on 600 and 700 class heli, steering servo on 1/10 scale buggies.

Dimensions(mm): 40.3x20.2x37.2
Weight(g): 52.4
Speed(@4.8V sec/60): .10
Torque(@4.8V oz-in): 133.3
Speed(@6.0V sec/60): .08
Torque(@6.0V oz-in): 166.6
Gear: Titanium & Aluminum
Bearing: 2BB
Case: Aluminum
25 Tooth Spline