The large Pro Angler rudder has been developed by Hobie to better suit usage in choppy and windier conditions, as well as for sailing, or instances where the user has loaded their kayak with poor weight distribution to the point of being bow-heavy. It is approx 1" longer and 1" wider - enough to make a difference in performance!. If you've experienced sketchy steering performance from the rudder on your Pro Angler it might be a good idea for you to fit your kayak with this larger rudder blade