As with all retractable truck bed covers, you will get water seepage along the sides and, of course, around your tailgate. If the cover sits for an extended period in a steady rain, you’re going to notice leakage. The aluminum panels are sealed against each other with automotive quality EPDM rubber seals.
Retractable covers offer unmatched flexibility for hauling and security, but they are not waterproof. They require some common sense when packing, putting items like tools or electronics into totes for extra protection. That’s the straight answer, and don’t believe a company that tells you otherwise.