To the people of pollen and dust particles with a static charge to the sports filter ★ Special filtration media captures small particles of 0.3 microns. ★ pollen and in the exhaust gas and effective in the prevention of harmful to small particles. * Material: anti-static fiber filter * Size: Medium. Large ◎ ■ 2 sheet 1 pair, featuring 3 different replacement filters on the market. ◎ 1 each per pack approx 69 hours of use and recommend you replace in the United States. - Can be used on all masks are common. * Color of the product may look different depending on the type of computer monitors, and display. Color or customer returns, exchanges are not allowed. In addition, the product details, logo, etc to the improved design is different, please understanding. May be altered to