Light Labs offers freezer racks for 15 and 50mL Centrifuge Tubes. These racks provide a robust and durable alternative to styrofoam or card racks for 15 and 50mL tubes. The indexed grid together with the clear lid provides you with ease of use in tube identification. To complement this further, you also have two opposing-face write-on surfaces. The distinctive green of the 15mL and blue of the 50mL racks make these easy to distinguish.