This is the Savox SC-0254MG High Torque Standard Size Digital Servo.

Features:

Over-spec refined design out performs ordinary servos.
Precision metal gears form a strong and solid framework.
Strict production and quality control of plastic components ensures long life and reliability.
Our servos are totally green – from materials to production, these servos are environmentally friendly.
Ideal for 30 size airplanes and steering for 1/8th scale buggies.

Dimensions(mm): 40.7X19.6X39.4
Weight(g): 49.0
Speed(@4.8V sec/60): .19
Torque(@4.8V oz-in): 86.1
Speed(@6.0V sec/60): .14
Torque(@6.0V oz-in): 100.0
Gear: Metal
Bearing: 2BB
Case: Plastic
25 Tooth Spline