The cylinder exchange device offers an automatic solution to switch between two cylinders of food grade CO2 when one of them runs out. Positioned between the CO2 inlet of the cooler and the low pressure outlets of the pressure reducers (not included) of each cylinder, the device is equipped with a light signal to indicate the active cylinder and a mechanical key to manually select the cylinder to be activated. The stainless steel box is designed to be wall mounted in a vertical or horizontal position, providing flexibility in installation.