Charles Owen Adults Fian Riding Hat Navy. The Fian Riding hat is the upgraded version of the Fiona, it has been trimmed to perfection using the finest Italian velvet and is ideal for everyday and competition wear. The Fian Riding hat features ventilation holes which are discreetly covered by the soft velvet and ultra slim deerskin harness which offers an elegant look. The Fian hat offers the slimmest proportions in the Charles Owen safety helmet range and incorporates the new SLIMS technology. The SLIMS technology utilises special processing of the EPS bead to increase the number of microscopic air bubbles for protection. This technology allows the Charles Owen designers to develop a new generation of ultra slim helmets.