This Luxor Double-Row Mobile Bin System holds 16 3 inch tubs, each capable of holding up to 20 lbs. The steel frame and sturdy guardrails with built-in locking system keeps the tough polypropylene bins securely in place during storage or transit, preventing them from unintentionally being removed. The mix-and-match rack system can also accommodate our larger 6 inch tubs (sold separately). Four rolling casters with two locking brakes make this storage cart easy to move around or secure in place. This versatile and functional storage unit is perfect for schools, garages or industrial facilities.