Ranging from +30 to -55 degrees, Big River Outdoors sleeping bags are built with quality and comfort in mind. They use 2-layer offset quilting construction, ultra durable water resistant canvas and ripstop shells and super cozy flannel liners. Their bags include 2-way zippers so you can zip 2 bags together. Additional features include adjustable mummy style hood, massive shoulder and zipper baffles, extreme space, and complete with 2 custom compression straps and stuff sack for simple transport.