For climatic and durability test of electrical and electronic components, simulated tropical and extreme tropical conditions, testing of drugs, chemicals, medicines, reliability evaluation of electronic components, accelerated life testing and thermal shock testing for infant mortality of components. Double walled construction with regular and gmp models. 100mm thick 'puf' insulation lagged in-between the walls to prevent loss of conditions. A well balanced cfc-free cascade refrigeration system with eco friendly refrigerant.