Size of connector in power adapter - WD My Book Essential


I need some help. I’m looking for replacement of power adapter for WD My Book Essential, but in Web I found 2 different informations about size of connector: 5.5 x 2.5 mm and 5.5 x 2.1 mm. Can anyone tell me something about that?

In this topic ( I found information that Ktec has connector 5.5 x 2.1 mm. But on this PDF from WD site (  the information is that connector size is 5.5 x 2.5 mm and this size is for many other WD products. In addition I tried to connect the power adapter from my TP-Link TL-WR1043ND router and it didn’t fit (I found that connector size is probably 5.5 x 2.1 mm). Connector from power adapter of Seagate My Expansion fits WD My Book.

The connector for WD looks like this:

Please help me because I need buy new power adapter today. I really appreciate your help. Sorry if my topic is duplicate of some older topic.


Maybe you should try contacting WD’s Technical Support about this. You can do so either by phone or email.

To Contact WD for Technical Support


Hello again,

I bough a week ago power supply for WD My Book Essential. I’ve got an information from WD Support that the connector size is 5.5 x 2.1 mm which is wrong. The truth is connector has size 5.5 x 2.5 mm and it’s 100% information. The information from PDF is good, but I don’t know why WD Support doesn’t know correct size. It’s important thing.