The Surge Suppressor should be secured to prevent movement in wind using zip ties or screws.
There are also four mounting holes directly under the lid screws. The lid must be removed to access them. They are 0.18″ in diameter and accept a size 8 or smaller screw. The screw should have a flat head, such as pan-head. A tapered screw like a wood screw or drywall screw tends to tear through the plastic and ruin the mounting hole. The wall of plastic is not thick so take care not to overtighten.