These multi combination racks made of high-quality Polypropylene (PP) have a unique rotate and lock design that allows you to choose the size of the rack according to your needs. These fully autoclavable racks can withstand temperature range of -80 °C to 121°C and can accommodate tubes of various sizes including 0.5ml, 1.5ml, 2.5ml, 15ml, 50ml and Ria Vials.