Medical and surgical apparatus for breathing purposes; humidification apparatus for medical and surgical use; respiratory apparatus and instruments for medical purposes; humidification chambers; medical humidifiers; humidifiers for use with respiratory therapy apparatus; humidifiers for use in laparoscopic surgery and open surgery; medical and surgical apparatus and instruments delivering medical gases and humidification therapy to treat respiratory diseases and conditions; breathing circuits, tracheostomy tubes, tracheal tubes, breathing tubes, nasal tubes, tubing connectors for medical use, tubing for medical use, all being for medical purposes; protective covers for sensors for use on humidification apparatus for medical and surgical use; parts, fittings and components for all the aforementioned goods