This is the Savox SH-1357 Super Speed Mini Digital Servo.

Features:

Light weight construction means less power consumption
The coreless motor brings output performance to new levels and ensures smoother, faster, and more efficient operation.
The metal case design not only looks awesome but also allows for cooler and smoother operating temps.
Our servos are totally green – from materials to production, these servos are environmentally friendly.
Ideal as a rudder servo on 450 class helis, CCPM servo on 500 class helis, and steering for 1/12th scale surface vehicles.

Dimensions(mm): 35.0X15.0X29.2
Weight(g): 26.0
Speed(@4.8V sec/60): .09
Torque(@4.8V oz-in): 26.4
Speed(@6.0V sec/60): .07
Torque(@6.0V oz-in): 34.7
Gear: Industrial Plastic
Bearing: 2BB
Case: Aluminum
25 Tooth Spline