This is a High Speed Digital Servo. It is designed to work with 450 Helicopters.

Features:
High Speed
Metal Gears

Specs:
Operating voltage range 4.8V-7.4V
Operating speed :
0.05sec@60°/7.4V
0.06sec@60°//6V
Torque :
3.7Kg-cm @ 7.4V
3.1Kg-cm @ 6V
Weight 20g
Working Frequency:1520us/333Hz,800us-2200us/
Ball Beaing : 2BB
12mm Coreless Motor
Size:23*12*27.5mm