I seem to always have to cut mine to size....then they stretch and get too big.

I find that a solar cover lasts 3 years, no more. It doesn't matter if I buy a cheap one or an expensive one...after 3 years I have to replace it. I haven't noticed a major difference in performance between a blue 12mil cover and a 16 mil clear one, having used both. So I just go with the cheaper one.

Last time, I actually got a 40x16 cover (usually 40' ones are 18' or 20' wide). Stretches anyway! I THINK this is the 2nd season for this cover, but, if it's the third, by late August, I'll know.....