- Reusable mask featuring 98% bacterial filtration efficency. Filters meet surgical mask standards. - Adjustable fit: Back of head and neck adjustable straps for a perfect fit. - All-day comfort: lightweight, breathable, ergonomic design avoiding ear pressure. - HeiQ V-Block* antimicrobial fabric treatment applied to inside pocket - Comes with 5 replacement filters. Non-reusable, can last up to 24 hours. Usage time depends on the use and environment.