Here below is the detailed technical specification of those series:

XQ-S8308D


Superfast New Brushless Servo XQ-S8308D from XQ-Power

Application: 500 to 600 class helis,1/10th racing cars,TOC, oil power,powervessel and
other industrial application

Bearing: Dual

Bushing Or Bearing: Bearing

Gear Type: Titanium

Height: 38.8mm

Length: 40.2mm

Width: 20.1mm

Motor Type: Coreless

Servo Type: Digital

Servo Voltage: 4.8 - 6.0V (Common Voltage)

Size Category: Standard

Speed: 0.068 sec/60 deg @ 4.8V;
0.56 sec/60 deg @ 6.0V

Torque: 104 oz-in (7.5 kg-cm) @ 9.6V;
118 oz-in (8.5 kg-cm) @ 12.0V

Weight: 1.97 oz (56.2 g)