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Big Agnes Lost Dog Sleeping Bag: 0F Synthetic


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  • Long/Left Zip
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  • Yellow/Navy - Unavailable

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Lost Dog Sleeping Bag

If your adventures don't stop when the days get shorter, the Lost Dog 0-degree sleeping bag will keep you warm throughout the winter. Even though this bag isn't as light as its down counterparts, you'll have peace of mind knowing that if a snowdrift blows into your tent, the hydrophobic fibers coupled with the water-repellent finish will keep you warm even if you get wet. Stay even warmer by zipping the Lost Dog to another Big Agnes sleeping bag for a snugglefest after your sufferfest.

For additional comfort, Big Agnes added a Free Range hood so you can lift your head without restriction and a Free Range foot-box so your feet can sit naturally at the end of your bag. And hey, if you need to warm up tomorrow's clothes before hitting the trail, there's plenty of space in the foot box for that, too.

  • 0-degree sleeping bag for cold winter nights in the backcountry
  • Hydrophobic fibers protects from early-morning condensation
  • Polyester lining feels soft while also managing moisture
  • Cordlock on the hood can be cinched with one hand
  • Pad retainer fits multiple sized pads for back- or front-country use
  • Mates with other Big Agnes bags to create a backcountry bed
  • Item #BAG00F2

[face fabric] nylon, [lining] polyester
water-repellent finish
Max User Height
[regular] 5ft 10in, [long] 6ft 6in
Shoulder Circumference
[regular] 69in, [long] 72in
Hip Circumference
[regular] 60in, [long] 63in
Foot Circumference
[regular] 49in, [long] 52in
Bag Length
[regular] 5ft 10in, [long] 6ft 6in
Draft Tube
no-draft collar, no-draft wedge, no-draft zipper
Pad Retainer
[regular] 20in-25in x 72in, [long] 20in-25in x 78in
full-length zipper
Fill Weight
[regular] 2lb 8oz, [long] 3lb 1oz
Storage Sack
Stuff Sack
rip-stop polyester
Stuff Size
[regular] 10in x 21in, [long] 10in x 21in
Claimed Weight
[regular] 3lb 8oz, [long] 4lb 1oz
Recommended Use
backpacking, weekend camping, winter camping
Manufacturer Warranty

Tech Specs

What do you think about this product?


>Rating: 5

Very comfortable, pad sleeve is a win

I've put it through the wringer
True to size
Size Bought
5` 10"
165 lbs

I used this for the entirety of a 6 month mountaineering/climbing/sea kayaking expedition in Chilean Patagonia last year. I've never slept better in a sleeping bag. There is no insulation on the bottom (a thick insulated inflatable pad is an absolute necessity), so all the material that would normally be under you is actually on top of you, like a big thick quilt. You can toss and turn and because of the pad sleeve, the sleeping bag doesn't move with you. I'm a stomach sleeper, so this is a very good thing. I will say that there are definitely warmer 0 degree bags out there, but its nothing a liner and long underwear can't solve. Two other things: as with every 0 degree synthetic bag, it's massive, especially the long. It'll take up 20-25% of a 70L backpack. It is also a darker color than the picture shows, and the interior has no sheen, like the picture shows. (To me this is a good thing - you don't stick to the bag as much if you get sweaty.) If you're in the market for a warm and ultra-comfortable synthetic sleeping bag, this is the one.

>Rating: 5

Seems great

I've used it once or twice and have initial impressions
True to size
Size Bought
5` 9"
200 lbs

This should be an awesome bag. I haven’t had a chance to use it in the field yet but have tried it out at home and it seems to be a well made and very functional sleeping bag. I ordered the long as I like to have plenty of room and this bag is just right. I will update my review after I use it in the field extensively this fall and winter.


Synthetic System Bags w/Flex Pad Sleeve

Big Agnes System bags with FireLine™ ECO synthetic insulation offer a roomy, rectangle-shaped sleeping space with an integrated Flex Pad Sleeve on the bottom. With technical fabrics and construction, 100% recycled, super-warm insulation, and tons of comfort features, these comfortable sleeping bags are designed to be lightweight enough for backpacking but cozy enough you'll want them in the campground too. The streamlined silhouette and Flow™ construction increase the thermal efficiency keeping you warm from head to toe. The Flex Pad Sleeve unites easily with your pad, and as you change positions over the course of the night, will keep you from rolling off your pad.