This Italian Dual Lance comes with a pre-installed QC Coupler on the High side and Chem Nozzle on the Low side. By turning the side handle, you open up the low side and automatically begin drawing chemical through your downstream injector. Dual Lances are the preferred cleaning attachment for hot water applications by applying chemical via low pressure and then cleaning with a pressurized stream while never having to turn the pressure washer off or change equipment.