This safety device is intended for all gas-fired heat-treating furnaces where shifting circulation of furnace is required to regulate constant temperature diffusion permitting faster heating up sessions. The box furnaces are customized for operations in laboratories, universities and dental operations. It offers a wide variety of structures and temperature scales. Maximized control functions of up to 8 burners with different functional levels. The product performs in single and double zone applications and has voltage ranges from 110 to 240 V AC.