This tent may not be ultralight for 3 season but it's pretty damn light for a 4 season double. Tunnel style design with 3 poles. I recently confirmed you can pitch it fly only and save about a pound and a half. Excellent condition.

https://www.terra-nova.co.uk/tents-and-spares/all-tents/blizzard-2-tent/

Min weight if you use both interior and exterior is 4 pounds 8 Oz.

You could definitely shave weight by replacing the guylines as well.

Looking for $350 shipped