The 60mm back band is size adjustable using a spacer cap that fits between the top of the cage and the cage clip. The 3mm spacer cap used here (left image) drops the entire cage into the back band space and therefore gives an equivalent 55mm back band to cage relationship. Variable length cage clips also allow the entire cage to slide inwards thereby tightening things up even more. The Guardian above right doesn't need this as the cage diameter is larger compared to the back band. It has an extended size cage clip for easing the cage outwards.

Both units should be worn at their largest setting first to avoid damaging the tissues during nocturnal expansion. Once settled, tightening up can begin if required.