This is the Savox SH-1350 Mini Digital Servo.

Features:

• Coreless Motor provides high speed, incredible efficiency, and low power consumption
• The Aluminum Case design not only looks good but also allows for lower operating temperatures.
• Totally Green – from materials to production, these servos are environmentally friendly.
• Ideal as a rudder servo on 450 class helis, and as a CCPM servo on 500 class helis.

*NOTE: Certain combinations of receiver and ESC have been found to cause "Brown Out" issues when combined with Savox servos. An external BEC or BEC stabilizing receiver capacitor may be needed for efficient, glitch free operation in low voltage electric applications. 

Specifications:  

• Speed @ 6.0V: 0.11 sec/60°
• Torque @ 6.0V: 63 oz-in / 4.6 kg-cm
• Weight: 26g
• Bearing: Dual
• Type: Mini
• Gear: Industrial Plastic
• Case: Aluminum
• Output Shaft: 25T Spline
• Case Size (LxWxH): 35x15x29.2mm