The liquid nitrogen dewar is made of anti rust aluminum alloy and structured with high-vacuumed super adiabatic multi-layers. It is light by weight and the daily evaporation rate of liquid nitrogen is very low. The product is applicable to long-term and low-cost indoor static storage of sperms, embryos, stem cells and other biological goods. There are different specifications varying from 2 liters to 100 liters for your ideal choice.