Airzone 55-Inch Trampoline & Enclosure Steel Patented enclosure entrance zips open, and support poles are covered with foam for further protection Soft bungee cord suspension system for kid-safe bouncing Easy to assemble with no extra tools or drilling required AirZone trampolines come standard with a limited one year manufacturer's warranty All AirZone trampolines and enclosures are independent laboratory tested to meet the most recent ASTM safety protocols