Buff Filter Face Mask in Blue | One Size The new Buff Filter Face Mask in Blue is a reusable face mask which is ideal for everyday use. Face masks have now become part of everyones essential wear. This face mask is great for daily activities like food shopping, using public transport or going for a run or bike ride. The BUFF® Filter Mask features a 3-layer, replaceable filter system in a washable mask design made from CoolNet UV+® fabric. Reliable and comfortable, featuring 98% bacterial filtration efficiency. Filters meet surgical mask standards. Features   Powered by HeiQ V-Block Adjustable fit All-day comfort HeiQ V-Block