The Sea to Summit Trek TkI Sleeping Bag delivers traditional comfort and value without a traditional design approach. Its unique design and thoughtful features provide you with maximum versatility for your backcountry adventures without having to break the bank. Its 30 degree rating makes it perfect for spring and fall camping and the two way full-length side zipper and secondary zipper offer ventilation and allow the Trek to be used as a quilt when fully unzipped on hot summer nights. In the spring and fall when temperatures can drop a little low, the vertical baffles over the chest prevent the down from migrating to keep your core warm while the hood and oversized draft tube retain your body heat. The Ultra-Dry Down that Sea to Summit stuffs the bag with retains its lofty warmth when you camp in moisture-riddled climates so you can take the Trek on all of your fair weather adventures.