Model Number: Y-90001-#4461 Key Specifications/Special Features: Material: antibacterial cotton, 100% pure cotton, PM2.5 air filterSize: adult, free sizeFunction: air pollution, car pollution, anti-dust, keep warmColor: grey, green, black, rose redAdvantage: 100% pure cotton, touch skin comfortable, good filtration, easy breath, fit faceSpecial: insert PM2.5 changeable filter, better filtration CodesDimensionSmallLarge Y-90001 Width 21±1cm 24±1cm Y-90002 Top-downlength 15±1cm 16±1cm Y-90003 Ear-looplength 30±1cm 30±1cm Y-90004 LightBreathingFilter 8x11±0.5cm 8x11±0.5cm *Other dimensions and color can be produced as per requirements.