HeatWeaver® plush lining Stretchable rib construction Advanced insulating yarn The Chunky Rib Heat Holders® Hat is exceptionally thermally effective, with a HeatWeaver® plush insulating liner specially developed to hold heat in. The super soft Heatweaver® lining feels great against the skin and it's also very efficient at using the heat that naturally rises from your head to keep you warmer for longer.
