The listing, USB Dual Port Bracket for Desktop PCs has ended.
Many desktop PC motherboards have extra USB headers (referred to as "internal USB connectors" in your motherboard documentation) that don't connect to the outside of the case where you can use them... unless you have a cable and bracket combination like this.
Simply connect the standard 9-pin USB internal cable to the header on your motheboard (it only goes one way; no documentation needed), then mount the bracket in an empty card slot on the back of your machine. Et voilá, two new USB ports will come to life.
Check your motherboard or PC documentation to ensure that you have a free "internal USB header" before bidding... then bid early, bid often, bid high... and good luck!