Water Absorbent Diatomite Coasters, Quick Dry Dry Sink Organizer with Grooves for Plant Cosmetic Bottle Hand Soap toiletriesSpecification  Color: Dark GrayMaterial: Diatom mudSize: 21x10cm/8.3x3.9inchPackage List: 4 x Square Diatomite Drink Coasters, 16 x Black Primer, 1 x Sand PaperAdvantageWater Absorbent Diatomite Coasters dry instantly and absorb excess moisture in seconds, protecting tables and furniture from moisture and damage. The textured surface of each tabletop protection coaster also prevents cups from sliding and prevents scratches on your furniture surfaces.ApplicationDiatomaceous Soap Holders are great for soaps, mugs, toothbrushes, tooth cups, makeup bottles, and anywhere you need to absorb water quickly and keep your desk/countertop dry.NOTE: Please make sure to choose the Quick Dry drip trays that fit the size of your cup; Do not let the plastic side directly near the bottom pot when using, so as not to damage the waterproof layer and affect the use.