Konjac is a natural herb grown underground in China with a soft texture for gentle cleansing that will not scratch while washing away dirt and oil from skin. For all skin types to use with or without cleanser to gently cleanse, and buff away blockages & dead skin cells. The cotton string provides a way to hang and dry the sponge between uses. Cleaning: Rinse and very gently press out water. Air dry away from sunlight. Replace monthly. Biodegradable. White: Pure Konjac Black: Activated Charcoal, Konjac *Sponges are hermetically sealed in wet state so customer can feel the sponge bounce *Sponge becomes hard when dried but fully softened again with water.