This is a mat in Carex, which was used in Japan for a long time. Carex is a material that resists to the heat and it's highly waterproof And breathable. When water falls on it, the water-repellent fibers repel it, and if there's too much moisture, the Carex fabric swells to keep it in. When dry, the Carex will spring back and allow air to flow naturally.
 
Dimensions: Diameter 165 x H10mm (M size)
Material: Carex *Please avoid washing directly with water, even if it has a natural water-repellent effect.
Spot clean with a damp cloth.
There will be some discoloration as you use it, but please enjoy it as a change over time.
Made in Japan