Elastic adjusters to avoid pressure on ear, resulting in a perfect fit for all convertible hook that changes the mask mounting from around ears to behind the head for usage for long hours. Highlights of the product bacterial filtration. Efficiency 95% anti-microbial finish. Breathable washable soft knit fabric on both inner and outer layer. Reusable anti-dust pollution. Sterilized for use. Easy carry on zip lock pouch. Melt blown layer for enhanced protection. How to use/care instruction.