1 lb 3oz (long), stuffs to about the size of a Nalgene. This thing will make any pack you own seem huge after you put it in the bottom. Construction quality is top notch (just like every Montbell product). The "super stretch" system is genius. Space in the bag when you need it, gone when you don't. Certainly not the warmest, puffiest bag out there, but it's not supposed to be. It'll keep you warm enough to get some rest and get back out on the trail. Best of all, this will shave pounds off (and cubic inches) off your back. Top notch product, highly recommended (just like every Montbell product).

I bought this bag based on universal positive reviews everywhere on the Internet - I have not been disappointed. Much has been made of the stretch on this bag - it's very much like a regular bag, but you can curl up, move your arms, twist into contorted shapes, and do everyone you normally do at home without realizing that you're in a sleeping bag. It really is a refreshing experience.
The bag itself is not cheap, but it measures up to other 40 degree bags I've had - perfect for July in the Sierras. Combined with the pack size (very small) and weight (it's light!), this is my new standard bag for non-winter trips. I'd probably opt for taking this in the spring/fall as well with an extra clothing layer - that's how comfy it is.

extremely lightweight. extremely compact. i definitely thought it was worth the extra cash.

Well actually I sleep very warm so I guess I'm hot but this bag is perfect for summer camping. We were above 8,000 feet and I think it got down into the 30s and I was plenty warm. The hugger feature really works the bag collapses around your body with the lightest of pressure (this bag is super thin and light) which reduces the volume of air your body is heating. I was dumb and didn't cover up well enough and ended up getting soaked by due and learned that an ultra-thin bag does well but it's got less tolerance so keep that in mind. One good thing is I got up and built a fire to dry out and was ready to spend a good long while but the thin high loft down dried surprisingly fast. It is impressive how well the bag worked for how light it was and even more impressive is how small it stuffs down to. I really like the whole package.

At first I didn't see the need to own a super light sleeping bag. After moving to Norther Virginia and spending a few warm summer nights in the wilderness, my 3lb+ 15 degree sleeping was too hot and uncomfortable to sleep in.

After doing a lot of research and finding the best deal, I came across the MontBell U.L. S.S. Hugger. Before I even hit the trail, I was extremely impressed by the stuff size. This sleeping bag is literally the size of a Nalgene 32oz water bottle, about 1/6 the size of my 15 degree bag. After a long humid hike to the camp site, I had my first night in the Hugger. The temperature was a steady 65 degrees. I slept great; not too hot or too cold. It is thinner for obvious reasons, so having a comfy sleeping pad is a must. I use a Z-Rest which is perfect for myself, but would recommend an air mattress for those who aren't comfortable sleeping on rocky/bumpy ground.

I bought this bag for a lightweight Central American backpacking trip. After lots of online research, this bag stood head and shoulders above the competition. I'll never go back to a non-stretch bag.
Extremely compact, light weight, and comfy. I move a fair amount when I sleep - the stretch in this bag makes it the most comfortable sleeping bag I've ever used. My favorite bag. Period.

Simple it does what it says buy it.