Bosch DirectConnect 40521 Wiper Blade - 21" (Pack of 1) Precision-cut natural rubber wiping edge removes the smallest droplets for a clear view and added safety Aerodynamic all-steel frame helps fight blade lift-off at highway speeds Graphite-treated wiping edge reduces friction and noise Dual steel tension springs supports the wiping edge for a consistent clean wipe DirectConnect installation system provides easy one-step installation Covers: Hook arm(9x3, 9x4, Audi)