While some brands are just starting to use Muscovy down in insulated products, Zenbivy has been doing it for years. But the brand claims its latest rollouts take the power of Muscovy fill even further. Going into 2026, Zenbivy will offer two new ultralight Muscovy technologies, which it says represent “the future of Muscovy Down.”
Muscovy down, for those unfamiliar, is a type of insulation derived from the Muscovy duck. Muscovy plumes are uniquely “clingy,” so they clump and hold together very well. It has a fast compression recovery rate, is very light, and doesn’t shift around as easily as goose down.
Zenbivy’s EXPEDry Muscovy 900FP launched in the fall of 2025. It is the first Muscovy with EXPEDry technology, which infuses the down with gold particles to enhance water resistance. Then, in early 2026, Zenbivy will launch its Ultrasonic Muscovy 950FP, which undergoes an ultrasonic washing technique to help fight odor.
Both of these insulation technologies will be available in the brand’s Ultralight Clip Beds this year, which include an ultralight sheet, quilt, and, as of Jan. 1, 2026, an ultralight insulated pillow. If you’re in the market for an ultralight sleep system with techy down fill, this new offering from Zenbivy might pique your interest.
Zenbivy Muscovy Technologies: What’s New?
EXPEDry Muscovy 900FP
Long-distance hikers and ultralight backpackers who frequently find themselves in humid environments will appreciate the water-resistant properties of this insulation. EXPEDry is a technology from ALLIED Feather+Down. It’s a process that infuses down clusters with gold nanoparticles, which break up water’s molecular bonds, making the down ultrahydrophobic while increasing evaporation.
GearJunkie has previously reviewed products that utilize this technology. Our experience with EXPEDry has generally been very good. It maintains its loft in humid, moist, or even outright drenched conditions and dries quickly. And because the gold particles are permanently embedded in the down, it doesn’t wear out like some coatings.
This is the first time a brand has used EXPEDry with Muscovy down. When combined, these two technologies could provide an exceptionally resilient sleeping bag for use in wet and humid weather.
Additionally, Zenbivy claims that the EXPEDry Muscovy is both ultralight and ultrapackable. You can already purchase Ultralight Clip Beds with EXPEDry Muscovy 900FP on Zenbivy’s site now.
Ultrasonic Muscovy 950FP
Zenbivy is launching its Ultrasonic Muscovy 950FP in early 2026. It claims the beds made with this fill are its lightest ever.
The Ultrasonic Muscovy insulation is a great option for serious ultralight backpackers seeking maximum warmth at the lowest possible weight. With Ultrasonic Muscovy, Zenbivy claims its 25-degree bag is 0.5 ounces lighter, and its 10-degree bag is more than 2 ounces lighter than its standard insulation. For true gram counters, that is not insignificant weight savings.
The Ultrasonic part of this technology has to do with how it’s washed. Zenbivy uses an “ultrasonic washing technique” that supposedly exceeds industry standards for cleanliness, making this specific type of duck down cleaner and “virtually odor-free.” The brand also claims this specific washing process uses 20% less water and energy than traditional methods, making it a more eco-friendly alternative as well.
BONUS: Zenbivy’s First Ultralight Synthetic Beds
If you can’t use down due to allergies or sensitivities, or won’t use it for personal or ethical reasons, Zenbivy can still cater to your ultralight needs. Alongside the EXPEDry and Ultrasonic Muscovy, in early 2026, the brand will also offer its Ultralight Beds in a synthetic insulation option for the first time.
The brand used PrimaLoft Gold insulation, which uses extremely fine synthetic fibers to create loft and trap heat. Supposedly, PrimaLoft Gold can achieve the same level of warmth as standard synthetic insulations at an even lower weight.
This is also the most environmentally friendly insulation option on Zenbivy’s menu. It claims that the synthetic insulation is made entirely from recycled waste, that the creation process requires 50% less carbon emissions, and that at the end of its life, it has the potential to be recycled. For eco-minded shoppers, this is a great option.
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