Behold, the G-Zero Primaloft® Jacket. Originally developed for the US military, Primaloft® is a super-lightweight synthetic insulation that’s renowned for its warmth-to-weight ratio. It’s tough, it’s breathable and it keeps you warm even when it gets wet—meaning it comes in particularly handy for long hikes when the weather can change fast. If you’re looking for a low-profile layering piece that works just as well over a sweatshirt as it does stashed under a big coat, you’re in luck.
