In vanilla Skyrim it is possible to equip a Falmer Helmet and circlet at the same time, however USSEP fixes this. I fixed it back. Also affects the Penitus Oculatus Helmet.

This one feels almost to cheaty for my tastes, however I was inspired to start uploading these reverts after seeing a request on the nexus forums by user roland734, and this was one of the examples he had given. Enjoy.