Inbetween mouth to lung and direct to lung where the draw is tighter than a direct to lung but not as tight as a mouth to lung leaving it possible to use the device either way.
Restricted Lung Inhale is used to describe when a device is capable of both a mouth to lung inhale and a more restricted direct to lung inhale giving a best of both worlds in some peoples opinion.
Inbetween mouth to lung and direct to lung where the draw is tighter than a direct to lung but not as tight as a mouth to lung leaving it possible to use the device either way.
