One Planet Sonder -5°C (671 grams) 2025

The Sonder is a streamlined, practical bag with versatile features, a spacious cut and a lighter build, designed for comfort and warmth year-round. It’s available in three temperature ratings (-3, -5, -8°C ISO 23537-1 limit-of-comfort rating), and small, regular and large sizes. The tapered rectangular shape gives space to move, while the Vertical V-baffle system and draft tube keep warmth where you need it (even as you wriggle around!). The shell is made from durable, water-repellent and highly breathable 10 D Vapour Vent V2 fabric, with a full-length YKK #5 zip and anti-snag locking slider. A separate foot zip allows it to be opened fully to manage warmth.

Now featuring Storm foot technology: water- and wind-proof, breathable fabric on the footbox.

Specs:

Down: 800-850 Loft hydrophobic down

Comfort Rating: 1°C

Limit of Comfort: -5°C

Extreme: -22°C

Weight: Small 671G, Regular 724G, Large 757G

User Height: Small 170cm, Regular 187cm, Large 200cm

Shoulder circumference: Small 155cm, Regular 158cm, Large 170cm

Hip circumference: Small 145cm, Regular 148cm, Large 160cm

Lower Leg circumference: Small 118cm, Regular 118cm, Large 120cm

Stuffsac size (Uncompressed): All sizes sml/reg/lrg 4.5L/4.5L/5L (15 x 18/18/19cm)

Temp Ratings

One Planet sleeping bags are rated using the international standard for sleeping bag performance, ISO 23537-1. (This is a revised version of European Standard EN 13537.) This means every sleeping bag has two ‘real world’ and one extreme rating. To determine what temperature might be most suitable for you see our technical pages.

• ‘Comfort’ rating is based on a ‘standard’ woman having a comfortable night’s sleep.
• ‘Limit of comfort’ is based on the lowest temperature at which a ‘standard’ man is deemed to be able to have a comfortable night’s sleep. This is the figure we use in our product descriptions.
• ‘Extreme’ rating is a survival rating for a ‘standard’ woman. According to ISO 23537-1, ‘a strong sensation of cold has to be expected and there is a risk of health damage due to hypothermia’. This is a survival rating only, and consumers should not rely on this rating for general use. The best guidelines are the comfort and limit of comfort ratings.

Ethically sourced down
Our down is ethically sourced, harvested and cleaned before purchase, with both the down and our supplier passing independent International Down and Feather Laboratory (IDFL) audits relating to ethical traceability. This means that the white down and feathers we purchase are from animals that haven’t been live plucked or force-fed at any point during the supply chain.