Weight/Thickness :99% of the surgical type masks are made of 3 ply, total weight is about 60-90g/m2. According to our customers' choices, you may like to choose these.Size :For adults: 17.5Ã9.5cmFor teens/ladies: 14.5Ã9.5cmFor kids: 12.5Ã8.5cm, 12Ã7cmBacterial Filtration EfficiencyOur BFE (Bacterial Filtration Efficiency) Test is showing an assuring result. Our Medical Mask can filtrate up to 99.99% of any bacteria that goes thru our medical face mask.