What's the ado about the Blue Kazoo? We've been partial to this sleeping bag for several seasons because it offers plenty of thermal performance and features without a lot of unnecessary weight. Comfort rated at 20F the Blue Kazoo is ideal for spring and summer mountaineering as well as three-season backpacking. The design features a stacked trapezoidal baffle system that keeps the down fill consistently in place to eliminate cold spots. Unlike a lot of conventional mummy sleeping bags that attempt to pin down your tired feet at night The North Face designed the Blue Kazoo with a vaulted footbox that offers a forty-inch circumference that's ideal for anyone who needs to shift around at night. Unlike some other vaulted sleeping bags made by The North Face the Blue Kazoo doesn't have a vented footbox so keep this in mind if you're planning on sleeping in warm spaces (the extended side zipper does a fair job at allowing some cooling capacity on warm nights). Whether you camp climb backpack or top summits in the summer the Blue Kazoo is a practical and highly functional choice for three seasons of your year.