This innovative sponge is a must-have for applying your foundation. The inner material is filled with silicone and the outer shell is thermoplastic polyurethane. This is a flexible plastic that is resistant to oil and grease, resulting in much less waste of your foundation. The material is also extremely easy to clean, making it more hygenic. All you need to do is rinse it with an antibacterial soap and cool water and then air-dry or dry with a paper towel!