Zpacks Octa® Fleece Thermal Bottoms beat the warmth and weight of all other long underwear in their class. Designed to be worn under your hiking pants in frigid weather, under shorts in cool weather, or worn as an ultralight sleep layer, these leggings are unmatched when ounces count.

Octa® Fleece features a soft, fluffy interior that traps warmth and keeps you cozy, and an abrasion-resistant exterior that withstands wear and tear.

Check out the rest of our Octa® Fleece Collection here.

From alpine ascents to nights around the campfire, the ultralight Women’s Octa® Fleece Hoody is designed to move with you and keep you looking great while doing it. Designed with a women's cut and offered in colors that flatter, this ultralight layer keeps you cute, confident, and comfortable wherever the trail leads.

Made with advanced Octa® fleece, it delivers exceptional durability, breathability, and a warmth-to-weight ratio that’s hard to beat. This pullover is designed for performance and versatility, featuring a soft, fluffy interior for unmatched comfort, a half-zip for quick temperature control, and a fitted hood to lock out the cold.

The spacious kangaroo pocket is perfectly positioned for access with a backpack belt on, keeping your hands warm and essentials within easy reach.

The Women’s Octa® Fleece Hoody is the go-to fleece you’ll reach for on every adventure.

Also available in a full-zip version. Check out the rest of our Octa® Fleece Collection here.

Shield yourself from summer sun and feel the breeze with the Trail Cool T-Shirt. This short-sleeve top is crafted from soft, stretchy, ultralight UPF 40+ fabric, providing breathable coverage and fast-drying comfort for long-distance hikers and trail runners who log big miles in the heat.

Our Trail Cool polyester fabric is designed to let the air through and pack down tiny. A spare t-shirt doesn't add much weight or bulk to your backpack, gym bag, or travel kit.

This t-shirt runs a little bit long and loose which is good for air flow and coverage. Size down if you are typically between sizes.

Check out the rest of our Trail Cool collection to discover our full lineup of breathable UL clothing.

Amazingly light but cuts the wind and holds the heat in with a layer underneath!

– Joe B., ★★★★★

The right layer can make all the difference. That's why the Ventum Wind Shell is purpose-built for those moments when a base layer alone isn’t enough, but an insulated jacket would be overkill.

A whisper-light layer that blocks the bite of the wind while staying highly breathable on the move, the Ventum Wind Shell starts at just under 2 ounces and disappears into your pack until you need it. 

Pairs well with an Octa Fleece Hoody to cut the wind and trap in warmth. Ounce for ounce the Ventum Wind Shell has the best warmth to weight ratio of anything we sell.

Whether you’re logging miles on a thru-hike or pushing big days in unpredictable weather, the Ventum Wind Shell keeps you focused on the journey, not your layers.

From alpine ascents to campsite relaxation, the ultralight Octa® Fleece Hoody redefines what a fleece can do. Built with advanced Octa® fleece, it delivers exceptional durability, breathability, and a warmth-to-weight ratio that’s hard to beat.

Featuring a soft, fluffy interior for unmatched comfort, a full-length zipper for easy layering and precise temperature control, and a fitted hood to lock out the cold, the Octa® Fleece Hoody is designed for performance and versatility.

The spacious kangaroo style hand pockets are perfectly positioned for use with a backpack belt, keeping essentials or trail snacks within easy reach.

Also available in a half-zip pullover version.

Check out the rest of our Octa® Fleece Collection here.

The Zpacks Waterproof Trail Notebook is designed to keep your notes from the field secure and dry when backpacking. This 3" x 5" (7.6 cm x 12.7 cm ) notebook lets you jot down your ideas, drawings, or journal as you go, knowing that the waterproof covers and pages will keep your notes protected from the weather.

This spiral-bound notepad lets you easily tear out pages to leave a note for a friend, or discard no longer needed pages to drop weight as you go on a thru-hike.

Pairs great with a Titanium Trial Pen!