Vinylon F is the functional fabric that has made our Kånken backpacks virtually indestructible for 30 years. With its combination of low weight and excellent wear resistance, Vinylon F is a fabric that retains its functionality even after many years of use! That's why it's been Fjällräven's best-selling backpack since it first saw the light of day in 1978! Perfect for school, day trips or cycling to work.