This 20° rated Ultra Light bag is a modified version of the Freedom Shelter sleeping bag.
The foot end of the bag is open so the sleeping bag will fit around the hammock and when you pull the draw cord tight the end is closed and of course all of the insulation is pulled together for a well-insulated foot section. The rest of the sleeping bag fits easily around the body of the hammock so the need of an insulated layer under the hammock is not necessary. I have made the insulated panel to go under the hammocks in the past but to the best of my knowledge mine and the others available do not work very well especially when there is wind. That problem does not exist with these bags. The hood end of the bag has a small opening that allows the hammock cord to feed through so it can be attached to a pole, tree or frame as I have pictured. The hood is a flat hood so it can lay away from your face in warm weather but when needed, it will close around your head much more efficiently than a contoured hood can.
It is available in one size only, equivalent to the standard long wide bag of 34″ x 90″.