Link multiple racks together for a customer rack solution. Autoclavable polypropylene (PP) heavy-duty construction is durable and chemical resistant. Multiple colors available for benchtop organization at a glance. Numeric markings for sample identification. Versatile design accommodates different tube sizes on each side. The four sides hold (4) 50mL tubes; (12) 15mL tubes; (32) 1.5mL tubes; and (32) 0.5mL tubes