Not applicable. This is a device accessory, not a topical product.
Contains 1 Extra Coarse roller head.
Source: Scholl product information.

Remove the used roller head from the device and fit the replacement until it clicks into place. Use light pressure and keep the device moving. Clean after each use. Replace about every three months.

Single extra coarse roller head
The grade for thick, stubborn hard skin
Fits Scholl electronic foot files
Can be used wet or dry
Sold singly, useful as a spare

For use with Scholl electronic foot files only. This is a coarse grade - use light pressure and do not over-file. Keep out of reach of children. For external use on feet. Not for use on broken, cracked or irritated skin, or over open wounds, moles or warts. If you have diabetes, poor circulation or reduced sensation in your feet, do not use without first speaking to your doctor or podiatrist.