JOLLY-1 has a steel housing and is oven coated with acid-proof epoxy paint and a 8mm thick aluminum heating plate that allows rapid heating up to 350 °C. Its position allows uniform heating of the entire surface. A solid structure makes the palate heater efficient and multi-purpose so it can be used as a thermostat by putting a steel tank on the plate or sand bath too. It ensures high safety as the controls are completely separated from the heating device. Temperature and setting for JOLLY-1 is obtained by a thermo-regulator with graduated fluid expansion probe where as JOLLY-2 having similar characteristics with different temperature controls is equipped with a an electronic, PB thermo-regulator with built in J thermocouple and red LED digital thermometer with outer PT 100 temperature probe. It allows temperature control on the plate or in the fluid. N.B. The max indicated temperatures refer to plate.