I'm selling my two-person bivy made by Dave at Miles Gear. It is 78'' long and tapers from a 108'' circumference at the head end to a 96'' circumference at the foot end. It uses a waterproof-breathable fabric for the top (not sure exactly what material it is, but it is very soft and warm to the touch) and tyvek for the bottom. All seams are seam-sealed. It weighs 19.4 oz on my scale.
There is a zippered entrance with a storm flap at the head end that allows you to fully seal up the bivy. And there is also a mesh window at the head end that can be zipped up to provide more ventilation while still giving bug protection.
I have used this bivy a total of 5 nights and have never had any problems with condensation, even when sleeping right next to a river. It is in good condition, but there are a few dirt spots from general use in the forest.
The bivy top:
The zippered mesh front window:
Foot end of bivy:
I'm asking $40 shipped CONUS. Please PM me with any questions!