The PHD M.Degree 400 K custom-made bags are for those who demand the best warmth-to-weight ratio, and who are prepared to pay for it, says Fiona Russell.

The PHD M.Degree 400k sleeping bag appeared on our guide to the Best sleeping bag for hiking. PHD makes all of its sleeping bags from start to finish in a UK factory. The company sources more than 95% of materials and components within Europe and minimises global transportation. The down is ethically sourced by PHD itself. This goes some way to explain the fairly eye-watering price of the PHD M.Degree 400 K custom-made, but it’s also a fully custom-made bag. As such, it fits me like a glove in width, length and at my feet.


Price: £882 | Weight: 560g (Standard Custom Made) Materials: 1000 fill power European goose down; shell and liner: 7X ripstop nylon with DWR | Temperature: comfort -9C | Features: Customised to suit customer size and needs; choice of four lengths and four widths; half and full-length zip, right or left, dual-construction design, oval-shaped footbox, various add-on options at extra cost including waterproof footbox/outer shell, stuff bag, mesh storage bag | Sizes: 16 sizes, depending on requests | Men’s version: Unisex


Slipping inside the bag is immediately cosy, and it’s easily the warmest bag I’ve tested. It’s also the lightest, and to achieve this PHD uses a different construction on the top compared to the underside to “optimise down lofting and shed excess bulk”. Weight is further reduced by the lightweight and wind-resistant nylon lining and shell fabric. I also chose a short zip.

The hood is smaller and more basic than other bags, and whilst it can be cinched around the neck it doesn’t have baffles. A couple of niggles include a sticky zip, and a drawcord for the hood adjuster that sits annoyingly in front of the face. Additionally, the narrow fit means stretching my legs whilst sleeping is not possible. PHD custom-made bags are for those who demand the best warmth-to-weight ratio, and who are prepared to pay for it.