SR100 Silicone Mask Pro KitThe SR 100 is designed for hard work during extended periods. Use it for the most demanding situations. The SR 100 is a silicone mask with a soft broad nose fit & deep chin cup. The new exhalation valve design creates an internal airflow that prevents particles from reaching the valve seat. SPECIFICATIONS Use: Half mask respirator for use with filters or supplied air Heavy duty use, full time exposure, long term work Material: Silicone rubber Head