After re-reading Collins' description of their PulsOx system I find myself a little confused by this:-
"Three duration options (small, medium and large) accommodate your aircraft’s descent profile – so you can choose the right size oxygen cylinder to get the aircraft to safety without carrying extra weight. Changing the descent profile is easy. Simply switch out the individual oxygen cylinder to the size that matches the new profile."
Can anyone with 787 experience translate this option into practical terms please? How does a flight crew know which money-saving option was adopted?