Common features that aid storage and transport are a fold-in-half frame with a middle safety lock, a compact folded footprint (about 35.5" x 12" x 3" in the listings), and a built-in carrying handle for easier lifting and carrying.
Many kids’ sandboxes use lids that convert into seating—often splitting into two bench seats with backrests—or close as split covers to keep sand clean and protected when not in use.
Example listings show long folding benches with a net weight of about 16.5 lbs. Portability features noted include a fold-in-half design, a compact folded size, and a built-in carrying handle to simplify transport.