The xtra is a new thing they have come up with. When I had my bed sprayed it cost me $180 more for the xtra. It is guaranteed in writing to not fade, chip or peel if it does they will fix it for free. I had my aluminum running boards sprayed with it as well.
LINE-X Xtra is the first product offering resulting from a partnership between LINE-X and DuPont Performance Coatings. This spray-on high performance bedliner is a “new benchmark” in exclusive composite coatings, as it combines the world renown strengths of DuPont™ Urethane Technology and DuPont™ KEVLAR®. LINE-X Xtra features include improved appearance, improved resistance to ultraviolet light (resists fading!!), more chemical resistant, and more stain resistant. In addition, LINE-X Xtra is specially formulated with DuPont™ KEVLAR® micro pulp fiber for extreme durability. Xtra is applied like a topcoat but actually migrates into the bedliner and achieves molecular mechanical bonding. Other bedliner brands may use a bedliner topcoat that only sits on top of the bedliner and does not achieve mechanical bonding. Many of those types of topcoats can be worn down with moderate use.