https://www.icondirect.com/
This is where I got my skylight for my Zinger ZT260BH. I’m in Canada so I ordered from the .CA site. So many variables with sizing so I suggest you accurately measure them. And get yourself some tubes of Dicor Self leveling caulk to seal it up after. I also used the sealant tape between flange and skylight.
For mine, the flange was about 1 1/4” all around from bottom of bubble. Actual size was slightly bigger than the factory one but it was way better.