It's an I2C-controlled PWM driver with a built in clock. That means that, unlike the TLC5940 family, you do not need to continuously send it signal tying up your microcontroller, its completely free running!
Output enable pin to quickly disable all the outputs.
Terminal block for power input (or you can use the 0.1" breakouts on the side).
Reverse polarity protection on the terminal block input.
Green power-good LED.
3 pin connectors in groups of 4 so you can plug in 16 servos at once (Servo plugs are slightly wider than 0.1" so you can only stack 4 next to each other on 0.1" header.
"Chain-able" design.
A spot to place a big capacitor on the V+ line.
330 ohm series resistors on all the output lines to protect them, and to make driving LEDs trivial.
Solder jumpers for the 6 address select pins.

Package Include:
4 * PWM Servo Motor Driver