This rack is ideal for serum vials (10-13 mm) and RIA or T3-T4 reaction vials (13-16 mm and 16-24 mm). Made of sturdy polypropylene to offer a rigid, light-weight and long-lasting rack. Convenient size for most elevated-temperature incubation water baths. Racks resist corrosion, rust, and are chemically resistant. Shatterproof. May be autoclaved to 121°C. From bottom of base to top of shelf, height of each rack is 1 5/8"". Height overall is 3 1/2"".