Five layer filtration technology Soft and breathable Each pack contains 30 filters Add a third layer of protection to your silk face mask with our PM25 Face Mask Replacement Filters! These filters include five layers of protective material: two layers of non-woven fabric; two layers of meltblown fabric; and one layer of activated carbon Simply tuck one into the inner pocket of your mask and enjoy additional protection from airborne particles *Please note, our silk face masks remain non-medical grade when used with a filter ITEMS AVAILABLE (IN STORES & ONLINE): Each filter replacement pack sold separately USAGE: Insert filter into inner pocket of face mask DETAILS: Each pack contains 30 filters Filters intended for single-use only FABRICATION: Five layer construction Two layers of non-woven fabric Two layers of meltblown fabric One layer of activated carbon SKU: SMSIFMSTFT Care Instructions: Replace filter every one to three days for maximum effectiveness Filters intended for single-use only and cannot be washed or reused Always remember to remove filter before washing your face mask. QE Home PM2.5 Face Mask Replacement Filters in Pack of 30