This is the Mummy Shape version of the Wren False Bottom Sleeping Bag. It’s narrower in the torso than the fetal position systems with a smaller differential cut. It’s meant to bend with your legs rather than allow room to curl up inside.
The Wren Sleeping Bag is a full sleeping bag with a false bottom. This is a full sleeping bag that wraps all the way around the sleeper, just without the insulation in the bottom where it is compressed and has limited effectiveness in a traditional bag. 12″ of the total torso circumference is the false bottom. This design pushes weight savings well below traditional bags and even below quilts, but performs totally draft free like a full sleeping bag. Venting is accomplished with the top drawcord. It has horizontal baffles, a differential cut, a puffy draft collar, and super dense chambers 160% overstuffed with Hyperdry 900 fill power down. It is important with any sleep system that it is paired with a sleeping pad rated to similar temperatures. It is especially important with quilts and false bottom bags and it should be noted that pads that utilize empty spaces are generally not suitable for these types of sleep systems.
See https://timmermade.com/sizing/sizing-sleep-systems/ for information on sizing.
This should be used with a Waterbear Balaclava or it can be used with other types of head insulation. https://timmermade.com/product-category/sleep-systems/balaclavas/
This can be paired with an overbag to manage moisture and boost it’s temperature rating. https://timmermade.com/product-category/sleep-systems/overbags/
See the “Technology” section on this site for information about this system’s features.