Hoggs of Fife Struther Waterproof Flat Cap Dark Green. Keep yourself protected from the elements with the Hoggs of Fife Struther Waterproof Flat Cap. Offering a fully waterproof, windproof and breathable cap, the Struther Flat Cap is truly a cap for all seasons. Made to be robust, the Struther Flat Cap is complete with a deep back construction for a better bit, a stitched down peak and a Teflon coating for extra protection.