The ZenBivy Bed is a Kickstarter-funded product that bills itself as the world’s first two-piece sleeping bag. It is a non-traditional style sleeping system that solves a few problems: it keeps the sleeping bag secured to the sleeping mat and it allows the sleeper to comfortably sleep in any position they desire. The unique design also allows for a lot of flexibility for different temperatures.

At first, when opening the ZenBivy Bed from the package, it feels like assembling a puzzle because there are so many separate pieces. These pieces are not that different from what goes on your actual bed: a sheet that attaches to your sleeping pad, a quilt, and a pillow, which includes an inflatable cushion and a soft textile case.

Weight

Since the ZenBivy Bed is a multi-piece system, the weight can vary depending on which pieces the sleeper chooses to carry with them. This is an awesome feature because it can be customized for more comfort for car camping or short backpacking trips, and it can be an ultralight product for longer trips where every ounce counts. So, if you are going to carry everything, sheet, quilt, and pillow, the total package weighs 2 lbs 10.2 ounces. This is certainly on the heavy side. Our top scoring bags in this review weigh around 1 lb, 4 ounces. But it should be noted that this is still less than the synthetic Big Agnes Bolten, which weighs 2 lbs 15 oz, and the ZenBivy’s weight includes a pillow, which is usually an unaccounted-for extra accessory. If you want to shed some ounces and leave the pillow and case at home, the sheet and the quilt together weigh 2 lbs 5.4 ounces. This is still fairly heavy, but not unreasonable. If you want to go light and fast in warm weather if you carry only the quilt it weighs 1 lb, 9.6 oz. This is quite light and very compressible, but it still weighs more than the top scoring lightweight full bags: The Z Packs Classic Sleeping Bag, the Therm-a-Rest Vesper, and the Feathered Friends Tanager.

Compressibility

With so many pieces, the ZenBivy is not the most compressible and packable option. All of the parts fit together into the stuff sack, but it is a rather large bundle. It can be made more packable by leaving parts at home, like the pillow or the sheet. If just the quilt is carried, it is quite a small package that fits nicely into a backpack.

Warmth

For a three-season sleeping bag, the ZenBivy is not as warm as most of the others in this test. It is EN rated at 34 degrees for Comfort and 23 degrees for Lower Limit. This is about on par with The North Face Hyper Cat (30 Comfort, 24 Limit) and the Therm-a-Rest Vesper (32 Comfort, 20 Limit). A “warm” sleeper (an average male) will be fine in this bag down into the 20-degree range, but a “cold” sleeper (an average female) will probably not be comfortable in this bed once temps dip into the twenties. Compared to the Sea to Summit Women’s Flame III (25 Comfort, 14 Lower Limit) the ZenBivy is not as warm. However, in the low 30-degree range and warmer, we think this bed is super comfortable and plenty warm, plus it is versatile enough to remain comfortable in much warmer weather. We think the ZenBivy Bed will work well for almost all summer conditions and can transition into the shoulder seasons of spring and fall fairly well.

Ventilation

The unique style of this bag offers many ways to regulate temperature. The different pieces of the bag can be paired together or used separately in different weather and conditions. For cool weather, the sheet and blanket can be attached, the foot box can be cinched closed, and the hood can be tucked around the head. In warm weather, the quilt can be used by itself, which allows for lots of airflow and the most ventilation possible in a camping sleep system. See the Features section below for a more detailed description of how these pieces work together.

Features

The real charm of this product is in comfort. Two frequent complaints about sleeping bags are that they are too confining to be comfortable and that they slide off the inflatable mattresses that are used while camping. ZenBivy solves both of these problems by creating a system that attaches securely to the pad and by making this system as comfortable and free as sleeping in a real bed.

Here is how it all works. First, the sheet. When you order a ZenBivy Bed, you specify what sleeping mat you already own or plan to use with it. ZenBivy will send you a sheet tailored to that mat’s length. (We chose to use it with the Therm-a-Rest Luxury Map, one of our favorite insulated sleeping mats, and this resulted in ultra-luxurious comfort. For a more backpack-ready set-up, we recommend pairing the ZenBivy Bed with a Therm-a-Rest Neo Air.) This sheet fits snugly onto the pad at the corners and is attached with thin straps along the back of the pad.

The sheet is composed of more than just a thin fabric layer. An insulated hood is attached to it, and there are zippers along the sides for attaching the quilt. Next, the sleeper has 2 options: zip the quilt onto the sheet for a fully-attached, bag-like sleep experience, or leave the quilt free and floating on top like a normal blanket. The pillow can tuck nicely inside the attached hood, and even if the quilt is attached to the sheet, it can be folded back just like a turned-down bed, and it is just as easy and comfortable to get into.

If the weather is cold you can make the ZenBivy tight and secure just like a regular sleeping bag. The foot box cinches closed to keep warm air in around the feet and you can snuggle into the hood. If the weather is warm, the blanket can be left unattached, folded back, or left off completely. This versatility allows for numerous sleeping positions that are difficult to achieve when trapped inside a mummy bag.

Durability

The textiles used in this bag are incredibly comfortable and soft. Most sleeping bags in this category prioritize weight savings, and therefore have slick, plastic feeling materials that provide the most durability for the weight. ZenBivy, on the other hand, prioritizes comfort. These materials also feel a little less fragile and more durable than the materials on other products in this test.

The shell material is a 20-denier nylon taffeta. It feels similar to standard slick sleeping bag material, but a little velvetier. The lining material is our favorite: a 50-denier polyester pongee. It feels soft and cozy, just like a regular bed sheet. Inside the ZenBivy Bed, encased in this soft material, is a more comfortable experience than in any of the other bags in this test. We also think this bag will last for a number of seasons, as long as you don’t lose any of the pieces.