Filter box is not included, and should be chosen accordingly

Liquid silica gel is soft, comfortable,durable, high temperature resistance, anti-aging, and suitable for long time wearing

Easy to change the filter box

Four-valve design, patented product, ensures 20% lower air resistance than similar imported products

Double exhalation valve design on the nose and mouth, reducing the circulation time of hot air and making it more comfortable. The upper valve is concealed, and the lower valve is protected with cover, which is not easy to be polluted.Easy to disassemble and clean

Design according to Asian face, elastic head strap could be adjusted to your head shape for a comfortable fit