This connector converter can convert a 7.9 x 5.55mm male connector with center pin to a 5.5 x 2.1mm male connector.



The back end of this converter is a 7.9 x 5.55mm female jack:



It can plug to a 7.9 x 5.55mm male connector, convert it to a 5.5 x 2.1mm male connector like this:



Note: 7.9 x 5.55mm connector with center pin is widely used on IBM/Lenovo laptop power adapters.