The lining is made up of a natural cotton terry cloth material for comfort softness and moisture absorption. The sole has a non slip tread pattern that will aid the patient in ambulating with confidence should they take a late night stroll. There are two optional 1/2 thick EVA wedges. Color: Black. Small: Men Up to shoe size 4.5 , Women Up to shoe size 6.5 | Medium Men shoe sizes 5-8 , Women shoe sizes 7-10 | Large Men shoe sizes 8.5-11 , Women shoe sizes 10.5 -13 | X-Large Men shoe sizes 11.5-14 , Women shoe sizes 13+.