I bought this air purifier and was installing the pre-filter that came with it. The instructions go "Carefully wrap the pre-filter around the HEPA filter so that the ends meet. Fasten the ends together with the fastener provided."
The pre-filter is longer than the HEPA is wide so does this mean
1)Wrap the pre-filter around the HEPA so the pre-filter's ends are touching and the pre-filter sits loosly over the HEPA
2)Wrap the pre-filter snugly around the HEPA so that the pre-filter's ends overlap
Here is pictures of how I have it now with slightly overlapping ends