{"product_id":"envelope-down-sleeping-bag","title":"Northern Warmth Envelope Down Sleeping Bag","description":"\u003cp\u003eA rectangular down bag for people who cannot sleep wrapped tight. It opens flat as a quilt, and two of them zip together into a double — which is what makes it the bag couples and van campers actually keep.\u003c\/p\u003e\u003ch3\u003eWhat the manufacturer states\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsulation:\u003c\/strong\u003e white goose down\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShell and lining:\u003c\/strong\u003e 400T 15D water-repellent nylon\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e envelope, opens flat\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 200 × 80 cm (Military Green: 200 × 73 cm)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJoins:\u003c\/strong\u003e two bags zip together into a double\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eChoosing the fill weight\u003c\/h3\u003e\u003cp\u003eOur own guidance, not a tested rating. An envelope bag has more air inside it than a mummy, so it needs a little more down for the same night.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e300 g\u003c\/strong\u003e — summer, festivals, indoors.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e400 g\u003c\/strong\u003e — British spring and autumn.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e600 g\u003c\/strong\u003e — cold autumn nights and van use in winter.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eNo temperature rating\u003c\/h3\u003e\u003cp\u003eThis bag has not been laboratory-tested to ISO 23537, so we do not print a comfort figure. \u003ca href=\"\/pages\/temperature-ratings\"\u003eHere is why\u003c\/a\u003e.\u003c\/p\u003e","brand":"Northern Warmth","offers":[{"title":"300 g \/ Navy","offer_id":48891051868345,"sku":"SU00055613-Navy-300g","price":99.0,"currency_code":"GBP","in_stock":true},{"title":"300 g \/ Military Green","offer_id":48891051901113,"sku":"SU00055613-Green-300g","price":99.0,"currency_code":"GBP","in_stock":true},{"title":"400 g \/ Navy","offer_id":48891051933881,"sku":"SU00055613-Navy-400g","price":109.0,"currency_code":"GBP","in_stock":true},{"title":"400 g \/ Military Green","offer_id":48891051966649,"sku":"SU00055613-Green-400g","price":109.0,"currency_code":"GBP","in_stock":true},{"title":"600 g \/ Navy","offer_id":48891051999417,"sku":"SU00055613-Navy-600g","price":129.0,"currency_code":"GBP","in_stock":true},{"title":"600 g \/ Military Green","offer_id":48891052032185,"sku":"SU00055613-Green-600g","price":129.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0814\/3100\/3321\/files\/e6dfe055-1474-4a75-9491-405557c00bd2.jpg?v=1787490459","url":"https:\/\/northernwarmthgear.com\/products\/envelope-down-sleeping-bag","provider":"Northern Warmth","version":"1.0","type":"link"}