Automatic, 1 piece box, himes, SBS, packed in corrugated. All barn sizes include slit locks to secure lid into either barn or box closure. Cedar Grove[R] accepted. The convertible locking feature on the handles allows the top of the box to fold flat for stacking and transport! Reassemble the top handles back into a barn box for an easy carry! Made from SBS paperboard, our barns are designed to keep food hot and fresh.