I have a mid tower case and i want a side panel with a window the measurements are 40cm high and 41cm wide and I don't know where to get one or find any help would be good and links also I want one to Fitt my case thanks
I doubt you're gonna find a side panel for your "mid tower case". Side panels aren't standard - it varies from case to case.
We don't even know what your case is lol.