Yes it sits just before the foamcannon bottle and where it mix the dilution from the attachement to the spray gun point of view. It's very uncommon that the foamcannon delivered with other than the 1.25mm orifice that would be the one to your pressure wash specs. It's it to a pro version of the foamcannon with alot higher specs than commercial PW? It's a big jump down from 1.25mm orifice to the 1.1mm orifice that is the step down in orifice. It can be that your PW starts pulses with the 1.1mm orifice. I would send a request to trinova or the seller which orifice you have in your foamcannon. I have just replaced the original 1.25mm orifice with a 1.30mm orifice to my foamcannon. Which I use with my kärcher k7 premium plus flex pressure wash 2600psi 2.6gpm specs. It's just over the specs to get up to the 1.30mm orifice. Will see on my next wash how the foamcannon works with the new orifice.