This connector one end is a male 7.4x5.08mm male connector with center pin for HP Compaq laptop computers, another end is female 5.5x2.1mm jack:
Important Note: The power adapter you are using with this connector tip should have right voltage and power that meet your computer requirement.
The back of this connector has female 5.5x2.1mm jack, which can plug to a 5.5x2.1mm male connector like this: