No pressure in bath/shower

[bidoup]

Hi all!
So I've been trying to resolve this for a while, without any luck...
I have pretty much no pressure in my bath/shower, I've replaced the catridge with no success. Now i'm looking at the valve and thought maybe that the little hole between the two main intake is to set the pressure but it does not seem to do anything....

any thoughts ?

 

[Mr_David]

what brand is that and do you have a model # and or picture of the cartridge?