"Ja biorę prysznic z (jedna) słuchawka prysznicowa"
Did you want to translate:
"I am having a shower using a (single) shower head"
It sounds stupid :-) Who normal says that he is having a shower using a shower head? :-)
Anyway, correctly in Polish, it would be:
"Biorę prysznic (jedną) słuchawką prysznicową"
We have the Instrumental case, we don't use the word "with" for that.