The Therm-a-Rest Questar 20 Sleeping Bag is a three-season bag which has Hydrophobic down filling Therma Capture seams & can be integrated to your Therm-a-Rest mat for highest comfort & warmth to weight ratio making this a fantastic choice of sleeping bag for spring through to autumn Therm-a-Rest have used Nickwax Hydrophobic Down for the insulating filling for this sleeping bag which boasts excellent temperature regulation dries three times faster absorbs 90 less water & maintains loft 60 times longer than untreated down to offer you an excellent performing highly compressible & comfortable sleeping bag ideal for those 3 season adventures They have combined this with their Zoned Insulation technology to place the fill exactly where you need it most & with their Therma Capture seams that trap your radiant body heat to amply for your warmth without adding weight & bulk The Questar has a toe-asis foot warmer which is a baffled pocket of insulation which helps rapidly warm cold feet inside the ergonomic footbox The Synergy Link Connectors also integrate the Questar with your mattress to ensure superior comfort with efficient warmth & the freedom to move as you like it also has quilt & blanket loops too if you want to layer a Therm-a-Rest quilt or tech blanket for the best night s rest possible