Supra NiTRO-X User Manual page 18

The packaging includes different sizes
of ear pads and Action Wings. It is
important that you select the correct
sized pads and wings for your ears. The
fit on these determine how good audio
experience and wearing comfort you will
get. To large pads will quickly become
uncomfortable to wear in the long run.
If you instead choose to small pads, the
result will be a thinner bass, disturbing
ambient noise and the earphones will
easily fall out of your ears.
The wings helps to fixate the earphone
in your ear so that the position remains
stable as you move around. Pads and
wings are washable in lukewarm water
and ordinary household soap.
Mounting Action Wings on earphones