Cold weather and stiff winds demand powerful upper-body insulation that can be layered into a system from beneath waders and bibs without bulk. Sitka's approach is to stop the wind dead with WINDSTOPPER® by Gore-Tex Labs while maximizing heat retention and mobility using PrimaLoft® Gold Insulation with Cross Core™ technology in the torso and sleeves. This cutting-edge insulator delivers a high weight-to-warmth ratio with the aesthetics and performance of down, while offering warm-when-wet functionality. Compression-resistant fleece is used in the lower torso to tuck easily inside waders or bibs.