Low gauge knit of 50% YAK and 50% wool. These yarns that tend to bulge out easily are often made with a high gauge and fluffy and light, which lowers the cost. However, Yoko Sakamoto purposely knitted it in an extremely dense and impressive low gauge to improve its cold and windproof properties. Even when worn alone, it has a strong presence and is warm. Also, the more you wear it, the more it adapts to the wearer's body and changes over time.