Ensuring a temperature of under 4°C for approximately 3.5 hours with the lid securely in place at room temperature, these racks offer reliable cooling. The Frosty Mate™ serves as an effective solution for transporting biological samples, chemicals, and more while maintaining a stable temperature over an extended duration. The Frosty Mate™ demonstrates consistent cooling, undergoing a noticeable color shift from green to yellow when the sample temperature drops below 4°C, providing clear and visible indicators of the cooling process.