Most waterproof sandbox covers and tarps are made from PVC-coated polyester, PVC (polyvinyl chloride) vinyl, or polyethylene.
Sizes range from small covers measured in inches (for example 21" x 21" x 5" sandbag covers) up to multi-foot tarps such as 5 x 7 ft and large 20 x 40 ft tarps (finished sizes near 19'6" by 39'6").
Common fastening features include grommets spaced for tie-downs, D-ring attachments, hook-and-loop (Velcro) closures on sandbag covers, and built-in carrying handles.
These covers protect against rain, snow, dust, debris and wind; some tarps also list UV resistance and the ability to withstand storms or heavy weather.