They ARE xenon bulbs, they're just not H.I.D. bulbs. Most people use the term "Xenons" incorrectly to refer to H.I.D.s, and I assume what you're really interested in are H.I.D.s

Switching to a Xenon charged bulb versus a Halogen charged bulb will give you much improved lighting (I always change mine over on my vehicles that don't have HIDs) for the price of a simple bulb swap. If you want the best quality, though, you will need to go to an H.I.D. (high intensity discharge) system, and that involves changing the electronics and lamps. What's shown in that ad is a Xenon bulb designed as a swap for a Halogen bulb; it's not a H.I.D. upgrade kit.