Color Switch Solo Refill is a single sponge specifically designed and cut out to replace the worn out sponge within the Color Switch Solo. It is recommended that the makeup artist replace the sponge after 2 or 3 months of use. as the sponge may loose its effectiveness after heavy usage. Sponge can be cleaned with warm water and hypoallergenic soap. Both sides of the sponge can be used. Discontinue use of the product if irritation occurs on eyes or skin.