Unique holders for round bottom flasks are molded from glass filled polypropylene, and are durable as well as easy to clean. The inside wall has a slight taper to the open bottom, allowing a variety of flask shapes to fit into one holder. The wide base keeps flasks stable. Side slots can be used as sight windows. Autoclavable at 121°C (250°F). 3 per package, 8 packages per case, except assortment (three each of 10, 25, 50 and 100mL sizes).