Ultra-high molecular weight polyethylene fibers with high thermal diffusivity are made of 6.0% ice silk, which is a cooling material. The "Q-MAX value (index of coolness)" achieves the highest level of coldness made of cloth of 0.5 or more! Even though it is a washable cloth mask, it shuts out fine particles down to 0.1 μm as a filter function. In addition to pollen and droplets, PM2.5 and fine particles were measured with a blocking rate of 99% in a sampling efficiency test. UV shielding rate of 99% or more, filter performance maintained even after 20 washes! There is also no change in shape. The length of the ear straps can also be adjusted, so it fits the line of the face firmly. You can use it comfortably even in the hot summer!