Double walled construction inner made of thick gauge stainless steel 304Q & exterior made of G.I. sheets powder coated. Cooling is by hermetically sealed compressors with CFC free refrigerant. Heating is by specially designed heaters. A motor with stirrer for better temperature uniformity. Temperature Controlled by Microprocessor based Auto tune PID digital temperature controller with PT 100 as sensor. Temperature Range; 0°C to ambient. A motor with pump for external recirculation.