The Universal Size SCBA Mobile Storage Rack LC12-4-U is designed for easy storing and transportation of any combination of (12) 30, 45, 50, or 60 min. SCBA, or fire extinguisher bottles. This mobile storage rack is manufactured of heavy gauge, square tubing, round bar, large 5 inch casters with locks and full length bottle valve protectors for increased safety which can also be used as push handles. The angled shelves, equipped with bumper guards, are dirt and dust collection free and allow free air flow for drying.