This connector converter can convert a 7.4 x 5.08mm male connector with center pin to a 5.5 x 2.1mm male connector.



The back end of this converter is a 7.4 x 5.08mm female jack:



It can plug to a 7.4 x 5.08mm male connector, convert it to a 5.5 x 2.1mm male connector like this:



Note: 7.4 x 5.08mm connector is widely used on Compaq, Dell and HP laptop power adapters.