A 210D oxford cover fastens over the top with hook and loop strips, which is what keeps rain, fallen leaves and neighborhood cats out of 48.5 inches of sand between sessions. The box stands 12.5 inches deep, roomy enough for two or three children to dig side by side, and each of the four corner seats carries 110 lbs. HDPE panels are polished with rounded corners so there is nothing to scrape a knee on, and the material stays odorless in summer heat. A perforated bottom liner lets water drain away, promotes airflow and lets you set the sand depth. At 26.5 lbs the frame stays put once filled yet can be repositioned in spring. Navy panels hide the dust that shows on lighter plastic, and the four seats double as a ledge for buckets and molds. Suitable from age 3, with sand sold separately.