Engineered for weight-conscious adventurers who refuse to compromise on warmth or breathability, the Bonfus Alphus series redefines active insulation. Built in collaboration with Bonfus and featured at Kaviso, these hoodies harness the unmatched warmth-to-weight ratio of Polartec Alpha Direct fabric. Designed to continuously release excess heat and moisture during high-exertion ascents while trapping vital thermal energy when you pause, the Alphus acts as a dynamic midlayer in cold conditions or a light standalone piece in milder weather. Whether you are shaving grams for a long-distance thru-hike or gearing up for fast-and-light alpine trips, the Alphus delivers high-efficiency thermal performance tailored to your preferred trail style.

Stripped down to the absolute essentials, the Alphus Pullover Hoodie is built for the ultralight purist who demands maximum warmth with minimal weight. By removing the full zipper assembly, this design reduces bulk, maximizes packability, and provides uninterrupted insulation across your chest and core. The cozy, ergonomic hood seals in warmth during chilly morning starts or breezy summit breaks, while the soft, brushed interior offers incredible next-to-skin comfort. Simple, durable, and featherlight, the Alphus Pullover delivers uncompromised active thermal performance for backpackers who measure every single gram.

The Alphus Full Zip gives you complete micro-climate control on the trail, combining ultralight warmth with instant adaptability. Featuring a smooth, full-length front zipper, this version allows you to dump heat instantly on steep inclines without taking off your pack or stripping off layers. The tailored active fit layers seamlessly beneath a rain shell or wind shirt, while the snug hood and draft-blocking high neck protect against sudden alpine breezes. It is the ideal choice for hikers who prioritize effortless on-and-off convenience, versatile temperature regulation, and maximum flexibility across unpredictable weather conditions.

Check out All Our Bonfus Accessories

A few simple care habits keep this garment performing at its best for years to come.

WASHING
Machine wash on a gentle cycle at 86°F (30°C) max using mild detergent. Avoid fabric softeners. Close the zipper before washing to prevent it from rubbing against the Alpha loft. Use a laundry bag to reduce microfiber release.

DRYING & STORAGE
Air dry is best. Alpha Direct is hydrophobic and typically dries in under 30 minutes hung or laid flat. Avoid tumble drying. For long-term storage, fold the hoodie rather than leaving it on a hanger — this prevents the knit from stretching over time.