The Callus Softening Kit contains an active callus remover, a PH neutralizer and all the tools to remove the dead skin cells from the heel. The tonic is a keratolytic alkaline solution that softens the protein bonds, making it easier for dead skin cells to be removed from the heels. It works only on the outer layer of the heel and softens the cornea stratum. It is the ideal product to apply to very dry and cracked heels. The Kit is was designed for home use to maintain ultimate results for very compromised and dry heels.