MarmotMicron 40 Long, Down Mummy Sleeping Bag, 650 Duck Down Filling, Very Light and Warm Sleeping Bag, Sienna Red/Tomato, LZ

Really well made, nice and lightweight. Ideal for summer use and maybe even spring and autum with some clothing.

Nice and light. Comfortable down to the rated values providing you have good ground insulation. At 4c humid night with heavy wind chill I was feeling the cold in this bag with 3.5R of ground insulation and two layers of clothing + a Sea to Summit sleeping bag liner.I don't think the bag can really go much lower than ~4C with a decent nights sleep, although in an emergency it would keep you okay down to around 0C I think. At around the 5C point layering up any more becomes inefficient from a weight point of view so you will probably want a dedicated winter bag/quilt.