This is the Spektrum S6390BL 1/8 Scale Brushless High-Speed/Torque HV Digital Servo. This generation of Spektrum surface servos provides you with the performance you need for any 1/8 scale vehicle application. High-Voltage applications up to 8.4V and feature all-metal case construction for the ultimate 1/8th scale performance.
Application: 1/8 Off-Road Brushless High Speed/Torque Servo
Torque: 312 oz-in (22.5kg-cm) @ 8.4V
Speed: 0.09 sec/60 deg @ 8.4V, at no load
Length: 1.58 in (40.1mm)
Width: 0.79 in (20.1mm)
Height: 1.47 in (37.3mm)
Weight: 2.3 oz (65g)