Maestro 24 Channel USB Servo controller by Pololu
The 24-channel Mini Maestro 24 raises the performance bar for serial servo controllers with features such as a native USB interface and internal scripting control. Whether you want the best servo control available (0.25μs resolution with built-in speed and acceleration control and pulse rates up to 333 Hz) or a general I/O controller (e.g. to interface with a sensor or ESC via your USB port), this compact, versatile device will deliver. This fully-assembled version ships with header pins installed.