24/7 Curls Instant-Set Curling Spray is activated by heat to offer 24 hours of super soft curls with a healthy sheen. This dry oil aerosol setting spray penetrates the hair shaft to instantly curl and define tresses, allowing the curls to have "memory" and remain defined throughout the day. Girls with curly and straight hair can just spray heat-activated 24/7 Curls evenly into sections of dry hair, and then curl with a heating tool (blowdryer, hot rollers, curling iron, or bevel iron).