How to Insert the Air Filter into the K9 Mask
Open the zipper on the top of the mask. Insert the air filter into mask with the "dark" side on top and "white" side on the bottom. Place the curve edge of the filter facing the nose of the mask. Align the air filter inside the mask so all edges of the air filter fit against the sides of the mask. Close the zipper on the mask.
What if the Air Filter Does Not Seem to Fit into the Mask?
Verify the size of the air filter by laying the filter on top of the outside of K9 Mask. Place it on the top of the mask and wrap the air filter around the left and right sides of the mask. You should see that the air filter is the proper size for your K9 Mask.