TRAPEZOIDS, MAN: Turns out this funky shape is ideal for helping sleeping bags ... DOWN: Light, compressible, warm to boot; what’s not to love about Down Fill? The Cosmic Ultra features 800 fill ...

The lightweight synthetic layer is all that's needed for warm weather in the range of 40 degrees or higher ... be difficult to zip. [Kelty Cosmic 20 Degree Down Sleeping Bag: $169.95 or less.