Once a vehicle has entered or exited, the walls automatically spring back to their vertical position. Entry and exit walls are supported every 12" with a patented "living hinge". Both long sidewalls are held upright by PVC sidewall assemblies. Simply swivel the feet to lower the sidewalls for storage or transport to another location. Drive-in/drive-out endwalls teamed up with Collapsible sidewalls offer the Ultimate combination - "Hands Free" convenience and an affordable design! Standard material of construction is Copolymer-2000ﾙ. XR5, polyurethane and other materials also available.