Anaesthetic delivery apparatus; ventilator apparatus in the nature of breathing systems comprised of tubing, hosing and connectors, and optionally including one or more of the following, namely, valves, reservoir bags, monitoring lines, pressure lines, and water traps all for use with medical ventilators; anaesthesia masks; filters for medical purposes, namely, filters for use in breathing systems in the nature of anaesthetic, ventilating breathing, and inhalation apparatus; filters for medic...