What are neoprene face masks with filters used for?
Face Mask Adult Neoprene – Proline
Viper Neoprene Face Mask - Joker
VEE Dust Mask With 2 Activated Carbon Filter, Washable and Reusable Breathable Mask for Pollen Allergy, Woodworking Mowing, Running, Cycling, Outdoor Activities : Amazon.co.uk: Health & Personal Care
Black Neoprene Face Mask Riding Mask with Valves + Carbon Filter Washable V4 | eBay
Sierra Montserrat Neoprene Mask | The Fair Cottage
SWISS EYE BASIC neoprene full face mask with goggles BLACK | Army surplus MILITARY RANGE
Activated Carbon Filter Mask | Easylife
Mycoal Neoprene Half Face Mask Junior - Grey - Ski Clothing & Accessories from Ski Bartlett UK