Petrel 10 UL Sleeping Bag

The Feathered Friends Petrel 10 UL is a premium 10°F (-12.2°C) women’s sleeping bag released for the 2026 season. Though the ideal height for a Medium is 5’9″, it fits a 5’10” hiker perfectly with extra room in the footbox. Featuring 950+ fill power down and an upgraded Pertex® Quantum Pro® shell, it is the ultimate gold standard for cold sleepers.

My full review is here if you want to learn even more about this awesome ultralight sleeping bag.

Feathered Friends Petrel 10 UL Sleeping Bag

My new sleeping bag is the Feathered Friends Petrel 10 UL, released for the 2025/26 season. I’ve been super happy with it so far. My full review here will provide more details.

Height Versatility: The “ideal” sleeper height for the Medium is 5’9″, but at 5’10” and 130 lbs, the fit is actually perfect for me.
No Restrictions: Whether I sleep on my back or as a side-sleeper who moves a lot at times, I don’t feel restricted.
Length: My feet don’t push against the end of the footbox, keeping them warm and comfortable.
Interior Space: There is enough internal room to tuck in my electronics and water filter on cold nights.

Warmth & Performance for Cold Sleepers

As a cold sleeper, I’ve found that the Petrel warms up really fast.

My Sleep System: To stay comfortable, I wear Merino 250 Base Layer tops and bottoms, a fleece-lined hat, and Heat Holders socks.
- My sleeping pad’s R value for backpacking is 6.2 (2020 Nemo pad R4.2 + Z Sol pad R2)
- My sleeping pad’s R value for car camping (in a tent) is 10.6
Layering for Extremes: I haven’t had to yet with this bag, but if temps dropped below freezing, I could add fleece pajamas. And I could also even fit my 55°F summer bag inside the Petrel as an extra layer for sub-freezing nights.
Hood & Draft Collar: The 3D contoured hood fits perfectly at 5’10”. Combined with the draft collar and face cinches, it seals in body heat so well that I’d likely be fine even without my fleece hat.
Footbox: The extra fill in the footbox works as advertised; my feet have never been cold in this bag.

Design Updates for 2026

Upgraded Shell: All-new Pertex® Quantum Pro® for better water resistance. (This is great if your tent has condensation issues like my backpacking one :D)
Reinforced Footbox: Features Pertex® Diamond Fuse 15 denier lining for extra abrasion protection.
Anti-Snag Zip Guard: A new strengthening layer along the zipper prevents snags, though it is a bit noisier than previous models.
Colors: I chose the Magenta, but it is also available in Cerulean Blue, Flame orange, and undyed.