- Prevents glasses from fogging up
- Helps with airflow to breathe better through face masks
- Approximately 1.5"
- $0.50 each
- Easy to install by cutting a hole smaller than the valve
- Ideal for masks with pocket filters as you have you exhale and filter that. Please do not use these with no filters/pocket filters
- These filters are not for medical purposes
This is a perfect addition to my masks. It helps give you a little extra fresh air inside your mask on a hot day. Customer service gave me terrific direction how to install them as well. Thank you !