Tightness in the cap and excellent temperature resistance make CryoTubes especially suited for storing samples at very low temperatures and, in general, where a high security for tightness is required. Manufactured from specially selected polypropylene, which combines a high degree of transparency with the ability to withstand low temperatures. CryoTubes, with inside treads, have a silicone gasket ensuring a tight seal. Recommended working volume and writing area are printed on the tubes. CapSicles are color coded inserts which snap into the top of the standard CryoTube screw caps for quick color coding of samples. CapSicles are available in 6 different colors and can be written on.