Lucas Oil Transmission Fix 10009 is designed to correct existing problems and prevent new ones in automatic transmissions. Made using an exclusive blend of petroleum-extracted additives Transmission Fix helps stop slips hesitation and rough shifting in high mileage transmissions. It lowers operating temperatures and stops foaming. It Can be added to existing fluid without draining any out. It is effective in extremely high percentage of cases. A must for motor homes towing vehicles and other vehicles with hard-working transmissions.