Option exo Description:Thermally activated, exo gives stronger, more energized, defined wave, along with all the healthy benefits of the thio-free ISO system. Offers lasting texture as well as unprecedented softness and shine, yet strong enough for luscious curls on long, short or resistant hair.Designed for:For Energized Curls on Longer and Resistant Hair Normal to Coarse Texture Tinted Hair in Good Condition (20 volume or less) Resistant or Gray Hair Long HairBenefits:Exothermic Activator For Off the Scalp and Condensed Techniques Can be Self Timed or Variable.