Icon is a new in-circuit oxygen monitor designed for use in veterinary operating theatres and intensive care wards. The Icon unit can be placed on the Fresh Gas Outlet of an anaesthetic machine or within the rebreathing limbs of a circle system, wherever the oxygen concentration needs to be known. The ICON unit uses a single AA Battery that has a lifetime of approximately 1 year when used for 8 hours a day every day. The sensing element is a longlife galvanic sensor that has a working life of approximately 2 years.