Incubators are manufactured with 22-gauge steel. Powder-coated exterior provides scratch and stain resistance. The interior is easy-to-clean aluminum. See-through polycarbonate doors with positive latches allow you to conveniently monitor laboratory applications. All analog incubators use a hydraulic thermostat for control of temperature and a separate on/off switch. The digital incubators utilize a PID controller and digital temperature input and readout. Over-range safety thermostat with a red warning indicator light, and a five hour timer are also provided.