The 2015 Backpacker Editors' Choice Award Winning Sonic series of sleeping bags are built to put a smile on your face when the cold weather is keeping most people out of the mountains. NEMO used all the best ingredients of high-end fabrics and 850 fill power down insulation paired with stretch construction at the knees for side sleeping. T hermo Gills regulate the internal temperature of the bag by as much as 20deg F without letting drafts in making this bag extremely versatile no matter the temperature you plan to use it!Features:850 Fill Power Downtek DownTemperature Rating: 15F / - 9CThermo Gills for regulating body temperatureStretch construction at the knees offers extra space for side sleepersOversized Draft CollarBlanket Fold provides tucked in comfortInsotect FlowGates prevent downward movement of insulationVideo -NEMO Sleeping Bags Design