The OEM Lenovo ThinkPad 90W AC Adapter is a rectangular-tipped power adapter designed for use with Lenovo ThinkPad laptops. It has a maximum output power of 90W and an output current of 4.5A, making it a powerful and reliable charging solution. The adapter is compatible with Lenovo laptops that require a 20V power supply, and it comes with the ADLX90NLC2A model number.