This set includes one blue -21°C Eppendorf® IsoPack and one Eppendorf® IsoRack for 0.5mL PCR tubes, and is designed for use with the IsoSafe (insulating box) as part of the Eppendorf® IsoTherm system. The IsoTherm system can be used to prevent enzymes from becoming inactive as well as for PCR sample preparation, sample transport, and slow thawing of frozen samples. The blue IsoPack will maintain a temperature of -21°C for up to 3 hours. The polycarbonate IsoRack holds twenty-four 0.5mL PCR tubes. IsoRack is stackable, autoclavable, floatable, and can be centrifuged in an MTP rotor. IsoPack Color: Blue. Temperature Maintained: -21°C For Up To 3 Hours. IsoRack Material: Polycarbonate. IsoRack Capacity: 24 Reaction Tubes. Tube Size: 0.5mL. Set Contents: One Blue IsoPack And One IsoRack. Eppendorf® #: 022510291.