This IBM ThinkPad R51 Series AC Adapter is 100% compatable with the IB1907 IBM ThinkPad R51 Series AC Adapter. Our batteries and accessories are made with high quality parts and are guaranteed to meet or exceed the original equipment manufacturers specifications at a reduced price. All batteries are tested for 100% quality control assurance. This IBM ThinkPad R51 Series AC Adapter includes a warranty to guarantee that it has no manufacturing defects.