Hello guys,

I need some help to identify a SMD component on a circuit board.
It is connected directly to the micro-usb port (Vbus, gnd, and both data signals I think).
I read X4 as a marking on the casing.
Do you know what component it could be ?
Thanks for your help !

 

Hello again,
After some research I found this type of component that seems common at an USB device input as an ESD protection (see attached picture).

What is your opinion about it ?

 

I think you correctly understand the purpose for which that part is used.