The CO Clear can be used in the scuba diving industry to warn the operator if there is a potential contamination of carbon monoxide gas (CO) before it reaches the cylinders/user. Product code: CO7503X55X9Y01. The CO7503X55X9Y01 package has a range of 0-25ppm in N₂ and comes with the CO Clear base unit, 3ppm and 10ppm alarms, 230V AC UK power supply, no repeater and 1 relay on alarm 2 with display