The clay humidifier brick is an essential piece of the Grotto Fresco, Grotto Mezzo, and Grotto Piatto: it maintains the overall humidity to keep your cheese fresher for longer. The piece is handmade in the US. It is fired at the perfect temperature and porosity to provide consistent humidity levels for your cheese, between 70 to 99% relative humidity. Submerge the brick in water for two minutes, wipe off the bottom with a dry cloth, then place in the bottom of the Grotto Fresco, Grotto Mezzo, Grotto Piatto. -Handwash only -4.75 inches long, 3 inches wide, 3/4 inch tall -12 ounces