This 90W car charger adapter with a USB port is perfect for HP laptops with a 4.5*3.0mm jack. It is compatible with various models such as the HP EliteBook and the 820 G3, 820 G4, 840 G3, 840 G4. The charger has a voltage of 19.5 V and an output current of 2.31 A.The charger's black color and compatibility with BTI brand laptops make it a convenient and reliable accessory for laptop users on the go. It is a great addition to your laptop accessories and provides a hassle-free and portable charging experience.