The product is oxidized so it's hard. You may use warm water mix together to use it. Exfoliate and brighten skin with Obagi Professional-C Microdermabrasion Polish + Mask 30%. This dual-action facial polish + mask exfoliates skin to prepare it for a powerful infusion of vitamin C. Designed to encourage a brighter, smoother and more youthful complexion, the Obagi Professional-C Microdermabrasion Polish + Mask 30% contains a unique dual-action technology to boost the bioavailability of Vitamin C by exfoliating before the mask treatment, optimizing absorption and boosting results.