Fordermenge = the output = 5.55 cubic cm/revolution = .33868 cubic inches/revolution. Max. Drehzahl = 2500 rpm. Max. Betreibsdruck = working or operating pressure 300 kg/cm2 = (kgf/cm2) = 4267 psi.
5.55 cm3/revolution = 0.00146615 US gpm or 0.00122083 Imp. gpm. Since most hydraulics are in US gpm I'll go with that. 0.00146615 x 2000 rpm = 2.9323 US gpm. Now this is the part that I'm not sure of. There might be an efficiency factor in here that I'm not aware of. JJ or someone who knows more can correct me.
I do know a bit of German but I wanted to double check so all I did was Google those German words and I had my hunches confirmed. The conversions I did with an app on my phone.