Sea to Summit’s Trek -1C Down Bag provides versatile temperature control and comfort. It features 650 fill duck down, a Free Flow zipper system for ventilation, and a generous semi-rectangular shape. The bag is not ultralight but offers a good balance of warmth, space, and adaptability.Sea to Summit says:The Trek Down Sleeping Bag is the perfect option for vehicle-based travels and overnight camping. With 650 FILL Power, this versatile and spacious bag uses an ergonomic design to offer additional warmth and comfort.Our VerdictSea to Summit’s Trek -1C Down Bag delivers a sleep system with versatile temperature control and a spacious, comfortable fit. This semi-rectangular bag utilises water-resistant 650 fill duck down to provide warmth rated to -2C.A key feature is Sea to Summit’s Free Flow zipper system, which has two sliders on the full-length and foot box zips and a half-length zip on the opposite side. So, it is a versatile bag with plenty of ventilation options if needed. The generous semi-rectangular shape offers roomy space.Other features include a comfortable fitted hood, a draft collar that runs along both sides of the bag, vertical chest baffles, and a horizontal lower baffle that mitigates down shifting throughout the night. The 20D recycled polyester shell is light yet sturdy, and two length options provide a dialled fit.While not an ultralight minimalist bag, the Trek -1C hits an outstanding balance of warmth, roominess, and versatility. – Reviewed by Ultralight Outdoor GearFeaturesDuck Down with Ultra Dry Down treatment for improved water resistance in damp conditions.Recycled polyester offers durability and comfort for lightweight adventures in a range of climates and conditions.The Free Flow Zip System offers temperature regulation and multiple sleeping bag configurations for added freedom in the outdoors.The Semi Rectangular Fit features a spacious design for added comfort and room that is best suited to car camping and shorter adventures.SpecificationsTemperature RatingEN13537:2012 Comfort: 3C | 37FEN13537:2012 Comfort Limit: -2C | 28FSpecsWeight: 1226g (excludes storage bags)Fill weight: 520gFits up to: 5.5 ft / 170cmInternal Width Shoulder: 145cmInternal Width Waist: 145cmInternal Width Feet: 120cmCompressd Size: 18LFitSemi-rectangular fit: Spacious and generous, a roomy fit for car camping and the occasional overnighter.Materials & ConstructionInsulation: 650 FILL Power, RDS-certified, Duck Down with Ultra Dry Down treatment for improved water resistance in damp conditions Fabric: Recycled 20-Denier Polyester shell and lining.Zipper: Free Flow Zip System: Primary zip – full length #5 with zip-plow and two sliders.Secondary zip – 1/2 length #5 with zip-plow and two sliders.Footbox zip – #5 with two sliders.Baffle Construction: Vertical chest baffles, horizontal baffles lower half and base, box wall baffle construction throughout.Collar: Vertical chest baffles, horizontal baffles lower half and base, box wall baffle construction throughout.Hood: Generous fitted hood with two soft touch adjustments. Fits a Sea to Summit regular pillow.Draft Tube: Single, synthetic-filled, draft tube along the top of all zippers.Intergration: Pairs with Women’s Sea to Summit bags, and STS quilts.Help & advice:Womens Sleeping Bags How do they differ?The Ultimate Guide to Lightweight Sleeping BagsTime-Saver Guide to Choosing a Sleeping BagSea to Summit Sleeping Bag & Quilt GuideAbout Sea to SummitThe EN13537 StandardAll About Down

Sea to Summit’s Trek -1C Down Bag provides versatile temperature control and comfort. It features 650+ fill duck down, a Free Flow zipper system for ventilation, and a generous semi-rectangular shape. The bag is not ultr