Before my first use I had thick callouses on my heels and on the sides of my big toes. The removed flakey skin powder builds up and sticks to the roller which is like.
Tuli S Heavy Duty Heel Cups Large Over 80kg
Considering this was my first use thats not too bad.
How to fix badly cracked heels. This unit worked wonderfully to remove them. I spent about 15 minutes on each foot. Its important to clean the roller after using it- otherwise it is not as effective.