Need an AC adapter for Dell Laptops/Notebooks with the following model numbers: Inspiron, Latitude, Studio, Vostro, XPS, Precision, Adamo? BTI has you covered with our premium 19V, 90W replacement power adapter. This product has been engineered to meet or exceed the original manufacturer's specifications and replaces the original Dell part numbers 87-22S8S-4EC, M22BAT-8. All BTI power adapters are manufactured and tested under our stringent quality standards and come with an industry leading 24 month manufacturer's warranty. BTI... True to the original.