These optional aluminum crossbars provide additional strength for FB2 and FB4 floorboards. This allows the user to inflate the keel at a higher pressure and improves motoring performance of the boat. The crossbars on FB4 greatly support the transom on Sport Boats to carry heavier engines. Set of 3 reinforcement crossbars (weight 4.4 lbs.) *Please note this item is not compatible with some floorboards. Please call to determine if your floorboards will accept reinforcement kit.