The newer version of the Undecover is made to apply to the hanging hammock. I think the ends close with Velcro, but it's been a while since I've seen a new one, so I'm no longer sure. That said, the Undercover wraps around the sides of the hammock with a bottom-entry slit matched to the hammock's bottom entrance. I think the Undercover would be in the way of entering the side-zip, but you may correct me if you can use them together without ripping something.
Hennessy Hammock afficionado and supporter.