Durable The Helly Hansen Featherswift is a stable and incredibly flexible trail running shoe. that we lace for all our daily needs. Helly Hansen upgrades this treadmill with ventilation and lightweight support. In addition, these shoes are environmentally friendly thanks to DWR treatment PFC-free, as well as recycled materials in the toe area, laces straps and top which reduces the amount of waste and reduces carbon dioxide emissions into the atmosphere.