The one I saw used at the marina had a swiveling head--not fixed like the one in the photos. And, the guys using it dipped the head in a bucket of warm water every few minutes, which kept the screen from clogging up. The guy with the boat next to mine used one screen for each side of the boat--total of 2 screens for a 30-T Catalina. Before he started the hull had several fairly large chunks missing in the paint. When he finished those areas were smooth as silk. I think he purchased his at Home Depot, but I'm not sure. I'll ask him when I see him this coming weekend.