How to wear shirt stays

1.  wrap around your thigh the shirt stays
(there is a left one , and a right one),

2. lock it in position, by inserting the buckle's pin, into the adjuster.

3. to avoid the clip losing its grip, DO NOT attach
the clip  in the middle, where the stitches are, as shown in the
left image.
ALWAYS attach the shirt stays clip away from the
stitches, in the thinner part, as shown in the right picture.