Good news! You don’t need to change the filter because the whole mask is the filter.
To provide the best seal possible we have sewn the filter directly into the mask. This way, the mask lifetime will last longer, up to 3-6 months on average. Please check our usage table below to learn about the life cycles for our masks.
If you have further questions, please contact us by email at info@cambridgemask.com or Chat button on our sites to connect with our Customer Service Team.