P.I.P. Microtube Storage Racks are made from polypropylene, are autoclavable, freezable, and resistant to most of the common laboratory acids and chemicals. Microtube Storage Rack has alphanumeric grid for an easy retrieval of microtubes. These racks have transparent hinged lids with latch, and their rectangular structure as well as the raised edges on the lid makes them safely stackable. They are available in 3 different models and various colors. The variety of colors facilitate classification.