Are international oxygen air negative pressure plugs all the same size and shape?

International oxygen air negative pressure plug size and shape are not all the same. The world of countries socket specifications, seemingly dazzling, but carefully summarized, is no more than 6 types, parallel double flat type plug. The two-hole thick round plug. The two-hole fine round plug, a vertical and horizontal triangular plug, double flat eight-type plug, three-hole thick round plug.