This is the Savox SB-2282SG "Monster Torque" Brushless Steel Gear Digital High Speed Servo. This high voltage servo comes equipped with dual ball bearings and an all steel gear train, yet weighs in at only 76 grams.

Specifications: 

Dimensions: 40.3x20.2x38.7mm 
Weight: 76g 
Speed @6.0V: 0.09 sec-60° 
Speed @7.4V: 0.075 sec-60° 
Torque @6.0V: 17.0 kg-cm (236.1 oz-in) 
Torque @7.4V: 23.0 kg-cm (319.4 oz-in) 
Gear: Unique steel 
Case: Aluminum 
Bearing: 2BB