- A protective, humidity-resistant styling spray, RUSK® Thermal Flat Iron Spray penetrates hair, infusing conditioning and controlling agents like argan oil and Thermplex™ to seal the cuticle, eliminate frizz, prevent curl reversion, and protect styles from environmental elements. Conditions and protects the hair internally and externally while smoothing and enhancing shine. A protective, humidity-resistant styling spray, it penetrates the hair, infusing conditioning and controlling agents to seal the cuticle, eliminate any frizziness and provide long-term memory, helping prevent curl reversion and making styles resistant to environmental elements. Conditions and protects the hair internally and externally while imparting smoothing and shine-enhancing benefits. Spray onto clean, dry hair prior to using a flat iron. Can also mist evenly on dry hair for style finishing.