A bivy is the most streamlined way to carry real shelter without the bulk of a tent. And after decades of building them, we've learned what fast-moving, weight-conscious trips call for: proven weather defense, durability, and a packable, minimalist design built for real backcountry conditions. Our bivy lineup covers the full range of fast-and-light objectives. The Alpine XT bivy delivers waterproof, four-season protection for exposed terrain and unpredictable weather. The Helium UL Bivy offers ultralight, low-profile shelter that disappears in your pack until you need it. The brand-new Helium UL Vestibule integrates with the Helium UL Bivy to create a modular shelter system that expands coverage and livable space when conditions call for it. And the Bug Bivy keeps airflow high and insects out on warm-weather trips when breathability matters most. Quick Comparison Model Weight Protection Level Best For Alpine XT Bivy 20.95 oz 4-Season Waterproof Exposed alpine terrain Helium UL Bivy 18.02 oz 3-Season Waterproof Fastpacking, thru-hiking, bikepacking Helium UL Vestibule 5.46 oz Added weather + gear coverage Expanding Helium UL system Helium UL Bivy + Vestibule 23.48 oz combined Expanded shelter system Extended backcountry trips Bug XT Bivy 16.38 oz Insect + ground protection Buggy terrain Alpine XT Bivy Maximum waterproof protection and breathable comfort for exposed terrain and unpredictable weather. Quick Specs Fabric: 3L Pertex® Shield Air with electrospun laminate (55% recycled nylon ripstop) Floor: 40D ripstop nylon with PU coating Weight: 20.95 oz / 594 g Seasonality: 4-season Why Choose the Alpine XT Bivy 3-layer Pertex® Shield Air delivers fully waterproof protection with exceptional breathability. Updated 2026 design increases interior volume for improved comfort and gear storage. High-volume toe box maintains sleeping bag loft and comfort. Large side opening and Fly Fastener system allows you to expose mesh for airflow and stargazing when conditions allow. Passive ventilation flap helps reduce condensation in cold or wet environments. Single DAC aluminum pole maintains structure and headroom. Reflective trims and included aluminum stakes secure the shelter in exposed camps. Choose This If: You need a four-season waterproof protection in exposed environments and want more interior space than a minimalist bivy provides. Shop Alpine XT Bivy Helium UL Bivy Ultralight, low-profile waterproof protection built for fast-moving objectives. Quick Specs Fabric: 2.5L Pertex® Shield NetPlus with hydrophilic laminate (100% recycled 30D ripstop upper) Floor: 40D ripstop nylon with PU coating Weight: 18.02 oz / 511 g Seasonality: 3-season Why Choose the Helium UL Bivy Fully seamed taped Pertex® Shield NetPlus balances waterproof protection and breathability in a ultralight 2.5-layer construction. Updated 2026 design refines fit and improves livability. Dual passive ventilation flaps increase airflow and help minimize condensation. Clamshell opening with no-see-um mesh provides ventilation and bug protection. Single DAC aluminum pole adds headspace without adding bulk. Six stake loops and a guy line loop improve stability in shifting weather. Choose This If: You want legitimate waterproof protection that weighs less than most one-person tents and disappears into your pack until weather rolls in. Shop Helium UL Bivy Helium UL Vestibule Ultralight add-on coverage that expands your Helium UL Bivy without the weight of a tent. Quick Specs Fabric: 15D silicone-coated nylon ripstop Weight: 5.46 oz / 155 g (23.48 oz combined with the Helium UL Bivy) Compatibility: Designed exclusively for the Helium UL Bivy Why Choose the Helium UL Vestibule Adds meaningful covered space for gear storage or weather protection with minimal added weight. Barrel attachment system integrates directly with the Helium UL Bivy for a clean, secure pitch. Designed to pitch with a single trekking pole to keep your shelter system ultralight. Waterproof silicone-coated ripstop balances durability and packability. Semi-translucent fabric maintains interior light while blocking precipitation. Reflective trims and included aluminum stakes improve visibility and stability. Choose This If: You want to extend your Helium UL Bivy into a more versatile shelter system—adding coverage and comfort without committing to the weight of a tent. Shop Helium UL Vestibule Bug XT Bivy Maximum airflow and insect protection for warm-weather trips where breathability comes first. Quick Specs Fabric (Upper): bluesign® approved polyester no-see-um mesh Floor: 40D polyester ripstop with PU coating Weight: 16.38 oz / 464 g Dimensions: 89.0 in x 26.0 in x 21.75 in Seasonality: Warm weather Why Choose the Bug XT Bivy Full mesh upper maximizes airflow while keeping insects out in buggy environments. Seam-taped waterproof floor protects from ground moisture. Updated 2026 design improves structure and interior comfort. Double aluminum pole system increases head and shoulder space. Large side opening allows easy entry and exit. bluesign® approved materials. Choose This If: You're heading into conditions where insects are the main concern and airflow is essential. Shop Bug XT Bivy Find Your Shelter Whether you're pushing into exposed alpine terrain, moving fast and light across long miles, or dialing in a minimalist summer kit, our bivy lineup is built to match the objective. Explore the full bivy collection and build the shelter system that fits your next mission. Shop Bivys & Vestibules Learn How to Set Up Your Bivy & Vestibule
