Adding a surface cleaner to your pressure washer will help in the following ways: you’ll clean more quickly, more effectively and more consistently than cleaning with a gun/wand. Save hours of time and effort with less physical effort and clean 4x’s faster. Those “zebra stripes” that are sometimes left from uneven power washing will be eliminated and you’ll be left with a uniform & clean surface on concrete or asphalt. Flat surface washers are also extremely effective in removing stubborn stains from asphalt & concrete. If you have set-in oil, gas or grease stains, you know how difficult it is to remove them. May not eliminate all the set in stains, but does a better job than a gun/wand. One of our favorite labor saving devices at WET.