The Sea to Summit, Women’s Altitude II is well thought out and a dream to use. It’s comfort rated to -10 degrees Celsius, and it definitely feels that cosy. The down has an ultra-dry treatment, so should perform well after getting wet or damp. The baffles are horizontal across most of the bag, but they run vertically on the torso to prevent the down fill dropping to the sides and leaving the top of your body without insulation.

Rating: 5/5 | Price: $399 / £400 | Available from: Alpine Trek | Weight: 1303g for regular, 80g compression sack | Fill: Ultra-Dry RDS Down 750+ loft | Shell: 20D Nylon | Zip: 2-way full length, 2 way half length, 2 way footbox | Length: 170cm for regular | Rating: Comfort -10c | Sizes: Regular & long | Men’s version: Ascent Sleeping Bag

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There’s a lot of zips around the bag, but they do all have a use. I really like the flexibility of being able to fold down the top half or open it up completely into a quilt. Two-way zips are fitted to each section, so you can just use it to stick an arm or a leg out, and tailor it as much as you need. The full length and footbox zips overlap, so they can be tricky to use without getting them snagged.

The hood is generous and can be cinched tight, and there’s large draft tubes along all of the zips. The one at the top can also be cinched separately to the hood with a simple to use drawcord. The drawcords are outside the bag though, so requires sticking hands out! There’s an internal pocket, but it’s quite small for a modern smartphone.

As a women’s specific bag, there’s additional insulation around the footbox and throughout the bag, plus a slightly different shape to a unisex bag. It’s narrower at the shoulders, and wider at the hips, which also means it’s comfortable for side and front sleeping without getting too tangled up.

It comes with a mesh storage cube, and a compression sack that seems water repellent and does a good job of getting the bag quite small. Overall, this is an excellent winter bag, but would suit shoulder seasons and even summer with the option to open it right up.