This is the best acid wave available on the market. Even though it has a "perm odor" while the solution is being applied, there is absolutely no odor after the hair has processed. The hair has a clean fresh scent afterwards. It can be used on all types of hair. The hair feels stronger and healthier after the perm. All other perms feel like a perm! Jeannie prefers the Arouse Plus on harder to curl hair and the Arouse on easy to curl hair.