Tarps are not considered a good cover. They can scuff the finish and they are not breathable. The ADCO covers are breathable, soft fabric, will not scuff. Some have said theirs didn't last very long. Our ADCO for our HTT was in near perfect condition at 7 years when we sold the trailer and included it. If you are getting it at CW, just tell them the make and model of your trailer and they'll know the correct size. Easier just to cover the whole thing, including spare and bumper. You'll need a ladder and a friend is helpful, but you can do it alone. READ ALL THE INSTRUCTIONS BEFORE YOU START. You'll save yourself a lot of grief to know exactly what to do first. Personal opinion is that they'll last equal to the care they're given and the way they're put on - pool noodles or some type of foam over the edges of the drip spout. You should be good for several years.