Zpacks Octa Fleece Thermal Bottoms

Zpacks Octa Fleece Thermal Bottoms

Zpacks Octa® Fleece Thermal Bottoms set a new benchmark for warmth-to-weight performance in ultralight base layers. Designed for versatility, they work just as well under hiking pants in freezing conditions, under shorts on cool days, or as an ultralight sleep layer when every gram matters.

Made from advanced 2.35 oz/sqyd Octa® fleece, these thermal bottoms deliver exceptional insulation at a fraction of the weight of traditional fleece. 

The soft, fluffy brushed interior feels great against the skin and locks in warmth, while the durable mesh exterior resists abrasion far better than most ultralight fleeces. Unlike fuzzy outer fleeces, it also resists collecting dirt and debris, making it more practical for long trips.An elastic waistband ensures a comfortable, adaptable fit, while the gusseted crotch allows unrestricted movement when hiking, scrambling, or stepping over obstacles. A convenient overlapping fly opening adds everyday usability.

Perfect on their own or paired with the Zpacks Octa® Fleece Hoody and Hat, these thermal bottoms are an ideal choice for hikers, fastpackers, and ultralight backpackers looking to maximize warmth without adding bulk or weight.

Revolutionary Octa® Fleece Technology

Made from 80 g/m² ( 2.35 oz/sqyd) Octa® Fleece, it delivers exceptional warmth at a fraction of the weight of traditional fleece. The unique octopus-shaped filament structure creates air gaps that trap heat efficiently, making it about 50% lighter than standard polyester fabrics of similar thickness.