The Atica 6 flowmeter bank is designed by Hersill specially for use in anesthesia by delivering a mixture of oxygen and nitrous oxide or oxygen and air from three independent gas entries. Only two gases can function simultaneously, one of which will always be oxygen. There a built-in automatic cut-off system in the delivery of nitrous oxide should there be an oxygen failure, and there is also an anti-hypoxic system. Atica 6 has dual tubes which measure the flow of each of the three gases. This combination ensures precise measurement and security when mixing with flows inferior to 1 l/min of each gas.