Cryo Freezer for up to 18 cryo-tubes from 1.0 to 2.0 ml. Lid and tube holders made of HDPE with foam liner. Enables critical, repeatable cooling rate of approx. 1°C/minute for successful cryo-preservation and optimum cell yield.Easy to use with 100% isopropanol and a freezing device. No direct contact between the tubes and the alcohol. Instructions for use printed on device. Stackable.