Idk, I wrap the hair, i pin down the rollers to a foam head to make sure it curls as close as posdible to the base, then I do a test curl on one roller with the waving lotion and time it, then i apply to all the other rollers for the determined time, rinse out, allow to air neutraize for 24 hours, and apply the chemical neutralizer on top of that if the hair was in good condition to begin with.