The Pro Cooler passes through the power adapter, and converts the normal single 360 a/v output into separate component, composite, VGA, S-Video and optical audio outputs. Each of these expanded output ports follow the same standard as other electronic devices which allows you to use any cheap standard cable you have lying around the house. Instead of paying $40 for the VGA adapter, simply plug in a normal VGA cord that can be purchased for less than $5.
Lastly, the Pro Cooler acts as a USB hub that expands the 360's single rear USB ports into 4 different USB ports. This allows you to connect more media devices, wired controllers, and other peripherals without exhausting all of your USB ports. Unlike the Nykon device which draws power from the power port and has a notorious reputation for malfunctioning and even ruining your Xbox 360, the Pro Cooler draws power from the USB port which is regulated diminishing the possibility of a surge.
Note: In its current configuration, the Pro Cooler does not work with Xbox 360 consoles that have an HDMI port built in, this includes the Elite and Halo, and newer versions of the Arcade and Premium.