FrostyMate™ Color Change Freezer Racks provide a visual indicator of temperature levels for easy reference during use and transport of samples. These reusable polypropylene racks have an operating range of - 86°C to + 121°C and can maintain a temperature of less than 4°C for almost 3.5 hours (with lid on) at room temperature. The rack dramatically changes color from green to yellow when its temperature rises above 7°C. Racks include an alphanumeric grid for organizing samples. Available in a 24-place option (6 x 4 array) that holds 1.5 mL to 2 mL micro tubes and six 0.5 mL micro tubes using an included adapter and a 96-place option (12 x 8 array) that holds 0.2 mL PCR tubes or strips.