Boekel Scientific Reversible Racks for Microtubes are designed to hold 0.5ml, 0.7ml, 1.5ml and 2.0ml microcentrifuge tubes. One side holds 1.5ml and 2.0 ml tubes, the reverse side holds 0.5ml and .7ml tubes. Ideal for numerous applications including freezing and autoclaving. The wells on each side of the reversible rach are easily identified with molded numbers. Made of the highest quality heavy-duty polypropylene to ensure long-term usage. We offer 3 sizes holding 60, 80, and 96 tubes per rack.