This is the Spektrum A6260 High Voltage Digital Ultra Hi-Torque Metal Gear Aircraft Servo. This servo was developed to provide incredible performance for giant scale airplane models. 

Features:

• HV compatible
• Quick release for servo leads simplify wiring and maintenance
• 340 oz-in of torque and a transit speed of .14 sec/60° at 8.4V offers impressive performance for giant scale models
• Metal gear train for robust and rugged performance
• Aluminum center section case doubles as a heat sink to keep the motor cool
  

Specifications:
Size Category: Standard
Type: Digital
Application: High-torque aircraft applications
Torque: 271 oz-in (19.5 kg-cm) @ 6.0V; 340 oz-in (24.5 kg-cm) @ 8.4V
Speed: 0.20 sec/60 deg @ 6.0V; 0.14 sec/60 deg @ 8.4V
Length: 1.61 in (40.9mm)
Width: 0.82 in (20.9mm)
Height: 1.25 in (31.8mm)
Weight: 2.30 oz (65.2 g)
Bushing Or Bearing: Bearing
Bearing: Dual
Motor Type: Coreless
Connector Type: Universal
Gear Type: Metal
Voltage: 4.8 - 8.4V