I’ve only had this bivy sack for a couple of weeks, but so far, it’s been a solid piece of gear. At just 347 grams, it’s ridiculously lightweight, which is perfect for my minimalist setup. The blue color looks nice, and it feels well-made and durable. I took it out on a campout recently and paired it with an ultralight tarp over my head while leaving my legs out the bottom. We got a little rain overnight, but my sleeping bag stayed completely dry, so the waterproofing checks out. It does breathe a bit, but I had to keep the top open to let the moisture escape—pretty typical for a bivy.Packing it back up was quick and easy, and it dried fast after use. I was able to fit everything into a 20L backpack for my hike in and out, which made for a really smooth trip. This is definitely going in my roadside duffel. If I’m ever in a situation where I need to camp overnight unexpectedly—whether outdoors or in an emergency—this could be a real lifesaver. If you’re looking for a lightweight, no-fuss bivy sack that does the job well, this one’s a great pick.

I was hoping to use this as a standalone summer bag but once I got it realized that is not it's use. This is a water resistant shell to go over another sleeping bag. It would really keep your inner bag dry. So it's great if you're cowboy camping or minimalist tarp camping. You could also put in a thin inner bag for summer time. It should add extra insulation with a bag that is marginal for the forecasted temps.It is light weight at 346 grams on my scale. It's well built and feels durable. The zip is smooth and doesn't stick. It has good quality.So even though I misunderstood what this bag is for, I really like it.

I tend to be pretty adventurous with my outdoor activities and have learned from experience that I am willing to be cold, hungry, or tired - but only one of these at any time! Each year, when I am winter camping near the Canadian border in MN BWCA, I try to improve or upgrade my kit somehow. A challenge that you quickly run into when it gets real cold is that the moisture produced from respiration, sweating, etc. will often settle onto your sleeping system and make it significantly less efficient at retaining heat. Goose down, the very best insulating material for a sleeping bag IMO, can be especially subject to degraded performance because the feathers phone moisture, compress, and can rapidly lose most of their of R-value. Because I favor products with down that has been "treated" with a hydrophobic coating this hasn't been a huge problem for me, but it's always in the back of my mind. For this year's upcoming trip, I am planning to take a couple of bug-out bag options to try and see how they work out for me.At first glance, this bag appears to be well constructed and reasonably water-resistant. At 12000 mm, it should not allow much moisture to cross the barrier into the bag (Note: "waterproof" is a myth). The zippers seem do a reasonable job and, bring at the side, should not be an issue for water intrusion, though I will definitely be putting some cold weather zipper lube on them. (Pro tip: graphite from a pencil works pretty well for this in a pinch.) You can usually get a feel for how well a fabric will work by rolling it up from the open end and observing how long it takes to get the air out. When I did that, the bag did hold air fairly well. The 40D rating should be more than robust/tear-resistant enough for a sleeping system.The major source of moisture is in every breath exhaled into a confined space. When the air temp is especially cold, the inside of my tent gets covered with a later of frost. When it is particularly windy, this can get knocked down onto my bag and soak in. I am hoping that a later like this will mitigate that. In fact, my only real concern that I have is that the fabric might actually be a little too resistant to moisture migrating from the inside out. Our bodies are constantly perspiring, which is a significant source of moisture in any sleeping system. It will be interesting to observe whether this does or doesn't have enough of a negative effect to alter the use case for this and how long it takes to manifest.For emergency use, I would personally lean more toward bags with fabrics that are lined with mylar. It is amazing how much additional heat they help to retain. (They have really saved my bacon in the past when the weather turned cold unexpectedly!) Though, in warmer weather this item would be pretty decent for keeping the rain off if you should you need to set up a hasty shelter.Bottom line: I think this is a good, lightweight additional layer for a sleeping system. It will certainly add one more option for getting a good night's sleep in the bush - the importance of which it would be hard to overstate!

I have two of these bags, a lefty and a righty. Amazon asked for a review of both, so I apologized for duplicate reviews. I'm 6"4' and 220 lbs, I wear a 35 inch sleeve shirt, so regular sized bags that frequently measure less than 30 inches wide are way too small for me. I can barely roll over in them and that is not conducive to a good night's sleep. This bag measures a whooping 345.4 inches wide at the shoulders! It is also extra deep so I can use the mummy hood feature without having to cram my toes into one corner trying to fit into a short bag. This bag is very, very comfortable for me and it will even accommodate larger guys. I think 6"5' might be the limit on the comfortable height if you plan to use the mummy draw string feature frequently. Even if you are a much broader fellow than I am, you should be very comfortable in this bag. The material of the bag feels good and the inside is smooth enough that it doesn't grab your night sleep wear, but it also doesn't feel "cold" like ultra smooth nylon. A major pet peeve I have with many bags is that the zippers stick or catch on the material when you are trying to unzip them. Since I really hate climbing out of my warm bag on a cold night, I usually stay in my bag until the last possible moment. A stuck zipper is a border line major crises for me at those times! I ordered two of these bags and messed with the zippers on both. My wife even crawled into one before giving her stamp of approval and didn't have any issues with the zippers.The retailer does not mention this online, but if you get a right hand and a left-hand version of this bag they zip together. I think that could be a major selling point and they are missing the boat by not mentioning that feature. Since they are mummy bags, you really need a lefty and a righty, unlike non-mummy style bags. There's really nothing that I don't like about this bag, especially the price.