The filter is designed to remain fully effective for at least 1 month in normal urban conditions.
RESPRO Face Mask Filter Sets - Techno / Sportsta / City Sizes: Med Large & X-Lge
RESPRO SPORTSTA MASK FILTER PACK
Respro Face Mask Anti Pollution Ultralight Bicycle Bike X-Large Black
RESPRO City Anti-Pollution Filter Face Mask for Cycling, Motorcycling, Running
RESPRO Techno Anti-Pollution Filter Face Mask for Cycling, Running Size XL
Black Neoprene Face Mask Riding Mask with Valves + Carbon Filter Washable V4
