Sturdy polypropylene rack is steam autoclavable. Holds up to 50 pipettes in a 5 x 10 arrangement. Top and middle decks have 16 mm diameter holes while bottom deck holes are tapered from 16 mm to 6 mm diameter to prevent pipettes from contacting table, avoiding contamination. Measures 8 3/4" L x 8" W x 4 1/2" H with handles.