These Adidas slippers are for narrow feet, or flat feet, because the straps are tight.
The straps are not adjustable.
The slippers are not actually narrow.
Measurements:
11" from heel-to-toe on the topside.
3 3/4" wide at the front (toe-side) of the strap.
8 7/8" circumference at the arch-side of the strap. This is the space for your foot 5" back from the front of the slipper.
The sole of the slippers are made of rubber.
The straps are made of plastic and cloth.
These slippers are lightly used.
They have been hand-washed clean.