The NEMO Siren 45 is a bed-style lightweight quit that weighs 21 oz and is insulated with 850 fill power RDS down. It’s an updated and redesigned version of the NEMO’s 30 degree Siren Ultralight Down Quilt, which has horizontal baffles instead of the new vertical baffles found on the Siren 45. The vertical baffles are a more efficient way to distribute the down insulation in a warmer weather quilt as well as being less expensive to manufacture.
Specs at a Glance
- Temperature rating: 45 degrees F \ 7 degrees C
- Weight: 21 oz \ 600 g
- Fill weight: 10 oz \ 285 g
- Insulation: 850 fill power down RDS (Duck)
- Liner and Shell: 10D Nylon Micro Ripstop w/ DWR, 10D Nylon Ripstop w/ DWR
- Gender: Unisex
- Girth 53″ x 48″ x 39″ (shoulder, hip, knee)
- Length: 78″ (fits up to 6′ 0″ in height \ 183 cm)
- Compressed volume: 2.16L (compression sack included)
The Siren 45 is designed to wrap around an inflatable sleeping pad in order to create a bed-like sleeping experience. It has a rectangular foot box and wide sides that wrap around the edges of your pad to block drafts. It also comes with a rudimentary pad capture system to hold the pad in place, although you can probably dispense with it in warmer weather when cold draft protection is less of an issue.
There’s nothing to prevent you from using the Siren 45 as more of a backpacking quilt, where you lie on top of a pad instead of sliding it inside the bag, or as a top quilt in a hammock without a sleeping pad at all. It’s certainly lightweight enough for backpacking, weighing just 21 oz, and it compresses down to a minuscule 2 liters when packed. But it’s probably best viewed as an alternative to a mummy sleeping bag for ground sleepers and one step less confining than NEMO’s innovative spoon-shaped sleeping bags, which were really the first sleeping bags specifically designed for side-sleeper use.
Pad Capture System
When you slide an inflatable sleeping pad into the Siren footbox, there’s still plenty of room inside the quilt for your feet, regardless of whether you’re a back sleeper or a side sleeper. However, it can be frustrating to get the tension on the string-based attachment system right so that you have enough room between the quilt and the pad to slide in from the head end. Very frustrating, in fact, since you have to flip the pad upside down to make any adjustments, which can be problematic in a two-person tent with another occupant.
My advice is to remove the string entirely and replace it with two or three horizontal pieces of elastic cord that will expand and contract as needed. This also makes getting the pad in and out of the footbox and past the elastic cords much easier than if you keep the crisscrossed static cord that comes with the quilt. There are six unobtrusive plastic clips sewn into the quilt’s seams. Simply string three pieces of elastic cord across them before you leave to go camping, rather than trying to configure this in a tent.
The top of the quilt has two metal snaps behind the neck to hold it closed around your neck, but you really only need the top one. Once you’ve slid your feet and body under the quilt, you’ll snap one of these around your neck and lie down on the pad. They’ll keep the upper part of the quilt in place, including the area around your shoulders.
There are also two adjustable cords sewn into the top seam of the quilt. These are used to tension the top so that it closes securely around your neck and blocks out drafts. They’re both easy to reach while you’re lying inside the quilt and help create a virtual draft collar around your neck when tightened. They’re much easier to use than the single neck closure cords found on many ultralight backpacking quilts and hold their tension all night.
Comparable Bed-Style Down Camping Quilts
|Make / Model||Weight||Price|
|Exped HyperQuilt 36||18 oz||$219|
|NEMO Siren 45||21 oz||$270|
|NEMO Siren 30||19 oz||$370|
|Sierra Designs Nitro 800 /35||20 oz||$250|
|Sierra Designs Nitro 800 /20||25 oz||$280|
|Therm-a-Rest Corus 32||20 oz||$200|
|Therm-a-Rest Ohm 32 UL||18 oz||$370|
|Zen Bivy Light Quilt 25||23 oz||$259|
The NEMO Siren 45 is a comfortable warm-weather camping quilt that provides a bed-like experience for people, especially side-sleepers, who find a hooded sleeping bag too confining. The Siren is different from most ultralight backpacking quilts because you slide an inflatable sleeping pad into it, rather than lying in your quilt on top of it. It has an extra-large foot box that wraps around the pad and keeps it securely in place and extra-wide sidewalls that are designed to wrap around the sides and underneath your pad to prevent any side drafts from chilling you.
The resulting experience of sleeping in the Siren 45 is very different from that of an ultralight backpacking quilt which does not “design-out” cold drafts to such a great extent and requires more expertise and experience to use. If what you’re looking for is something that is less intimidating to purchase and more predictable to use than a backpacking quilt, I think you’ll be pleased with the Siren 45. It is a well-made, comfortable, and warm camping quilt to sleep under, easily vented if you’re too warm and easy to snug down if you need to ward off a chill.
Disclosure: NEMO provided the author with a quilt for this review.Editor's note: Help support this site by making your next gear purchase through one of the affiliate links above. Click a link, buy what you need, and some sellers may contribute a small portion of the purchase price to support SectionHiker's unsponsored and independent gear reviews, beginner FAQs, and free hiking guides.