Wanna see something amazing? Take a look at the G-Zero Primaloft® Jacket. Primaloft® is a super-lightweight synthetic insulation that was originally developed for the US military, so its warmth-to-weight ratio is basically unmatched. The insulation offers the perfect mixture of breathability and warmth, while the nylon shell offers some water resistance that will come in handy during unpredictable weather. This low-profile jacket is the perfect layering piece, going just as easily over a sweatshirt as it does under a coat.