The ADVC110 acts as the intermediate step between the analog video signal from the finish line camera and the digital firewire cable that connects to the computer. (See diagram under more photos). The ADVC110 is a professional grade converter field tested and proven not to drop frames and is the only product of its kind that Eagle Eye Digital Video promotes with its timing systems. This item is powered by an IEEE 1394 FireWire connector. No additional power source is required if using a desktop computer. If your timing system runs on a laptop computer you will need to purchase the additional power source. The ADVC110 is not available in stores.