A great concave design lets the OXO Good Grips Coasters contain liquids from condensation buildup * Made of sturdy silicone, the set of 8 coasters is completely dishwasher safe * Grooved pattern holds liquid and promotes air flow so coasters won"t stick to glassware * Use either side, since the concave design is same on top and bottom * Available in a choice of colors for easy accessorizing