RZ Dust/Pollution Laboratory Tested F1 Scentless Active Carbon Filters Size Small/Youth/Medium 3 - Pack ? Neoprene Construction . Tough-duty durability 99.9% Replaceable Active Carbon Filters Dual one-way discharge valves . Reduce condensation Adjustable nose clip .Prevent fogging Adjustable Velcro Strap . Universal fit Filters tested at Nelson Laboratories, USA