Apeks Flight Nitrox Regulator The Flight Nitrox Regulator from Apeks is available as DIN only. The Apeks Flight Regulator from Apeks is the lightest regulator in the world! This revolutionary regulator has been made using advanced composite materials selected for their optimum strength to weight ratio & is extremely easy to use. As they leave the factory, standard Apeks regulators are suitable for use with oxygen enriched gasses (i.e. Nitrox etc.) providing the oxygen content does not exceed 40%*. For mixtures containing more than 40% the regulators must be professionally converted to oxygen service by an Authorised Apeks Technician through an Authorised Apeks Dealer. * For regulators purchased within European Community Countries, Apeks must adhere to the European Standards EN 144-3 & EN 13949 which state that any regulators purchased, which are for use with oxygen content of over 21%, must use the special M26 fi tting & the standard regulator fi ttings must not be used with mixes over 21%.