Back by popular demand and re-engineered for even better technical performance, meet your new favorite insulator. Made of a premium soft and stretchy Japanese fabric with an added exterior treatment to make it water and stain resistant. This fabric is then filled with a light-weight synthetic insulation and heat bonded. Featuring Merino wool fabric inserts specially developed into a grid-like pattern with an open structure for optimal wicking and breathability. Additional ventilation options make this the perfect jacket to wear under your favorite KJUS shell or by itself on a Spring day.