Therm-a-Rest Questar 0F/-18C Sleeping Bag4 season down sleeping bag. This is the field proven, feature packed down bag you've always wanted. We've loaded this bag with the comfort features that Therm a Rest bags are known for. Our SynergyLink Connectors integrate the bag with your sleeping pad while allowing our Zoned Insulation to keep fill where you need it most. The fit of the bag has been perfected in our onsite cold chamber to create our W. A. R. M. fit that allows room for multiple