Featuring a patent-pending design that allows users to instantly verify a correct seal on their respiratory mask, ensuring maximum safety with every use. Instant Seal Check: With the innovative PressToCheck™ system, you can easily confirm that your mask is properly sealed each time you wear it, providing confidence and peace of mind in hazardous environments. Award-Winning Innovation: The PressToCheck™ Filters have earned recognition, winning the prestigious BSIF Product Innovation Award.