Shackleton is expanding its apparel lineup for Spring/Summer 2026 with the launch of the Erebus Jacket and Hawkes Gilet, two new active insulation layers designed to provide warmth, breathability, and all-day comfort.
Active insulation is increasingly popular among hikers, climbers and trail runners looking to create layers that can be worn during movement rather than repeatedly added and removed throughout the day.
The category has grown steadily over the past decade, helped by brands such as Patagonia, whose Nano Air (see also: Patagonia Nano Puff Hoody review) helped popularise the idea of a jacket that could be worn throughout a day in the mountains.
Shackleton's new pieces can do just that while also adding a sustainability-focused twist by using recycled ocean-bound plastic.
They use Clo VivoOcean insulation, a synthetic fill made from recycled fibres recovered from plastic waste collected near coastlines before it enters the ocean.
Unlike traditional synthetic insulation such as fleece jackets, the material uses a perforated construction that is said to allow excess heat and moisture to escape more easily during periods of high exertion.
Shackleton says the technology delivers up to 30% better (!) breathability while maintaining insulation in cold weather.
The brand also claims an RET rating of 0.62, placing both garments firmly in the highly breathable category.
Built for moving fast
Shackleton says the flagship Erebus Jacket has been designed with climbing and scrambling in mind, for enthusiasts seeking a lightweight layer that handles changing conditions from the valley floor to the summit.
It combines the VivoOcean insulation with a windproof, breathable shell made entirely from recycled materials and finished with a PFAS-free C0 durable water repellent treatment.
Not quite a waterproof shell, but enough for changeable weather around the countryside.
Underarm gussets and articulated sleeves are intended to improve freedom of movement, while a two-way front zip and harness-compatible pocket placement should make it easier to use alongside climbing equipment.
A lighter option for layering
Alongside the jacket sits the Hawkes Gilet, which uses the same insulation technology in a sleeveless format.
Designed as either a standalone outer layer or part of a three-layer mountain system, it offers core warmth without restricting arm movement.
Both garments feature four zipped pockets, microfleece-lined collars, and two-way zips, while the recycled shell fabric, recycled insulation, and PFAS-free finish help keep environmental impact lower than that of more conventional insulated layers.
The Erebus Jacket and Hawkes Gilet are available now at Shackleton.
