Buff Filter Mask | Burj Multi | 2021 The new Buff Filter Mask is an essential accessory for daily activities like grocery shopping, using public transport or going for a run. The BUFF® Filter Mask features a 3-layer, replaceable filter system in a washable mask design made from CoolNet® fabric. Reliable and comfortable, featuring 98% bacterial filtration efficiency. Filters meet surgical mask standards. The fabric technology HeiQ V-Block protects the inside pocket fabric of the BUFF® Filter Mask from microbes and germs. Features   Reusable mask - 98% bacterial filtration efficiency. Filters meet surgical mask standards. Filters included. Each mask comes with five replacement filters.