Purchased this to spray a sealant on my stamped drive and patio, but have not used it yet as I wait for cooler weather in mid-to-late September. Got tired of paying $900 every two years -- last one lasted only through 2013 summer. I researched this Chapin product and found it to be top-drawer. While consulting with a local supply house that sells concrete sealants, etc., the tech helping me asked what sprayer I had to do the job. When I told him the Chapin Industrial 3.5-Gallon Concrete one, he commented this is the "very best." At that supply house I know these sell for well over $100, so buying from Amazon.com was a great deal for ca. $80 +/_. For long-term use the sprayer MUST BE CLEANED PROMPTLY AFTER EACH USE, which for the sealant I'm using is zylene. Should last for years and avoid paying for poor workmanship by those who claim to be "professionals."