Review on Weller WCC104 Solder Cleaning 101 6Mm by Chris Litton

They go perfectly with my WLC100 Soldering Station. When wet, they tend to puff up, which isn't a big deal. The problem, however, is that when rubbed with a hot soldering iron tip, they give off an odor that permeates the entire room. It took me a few days to figure out what was causing this smell. As others have pointed out, they also don't have slots which is usually expected. Instead, I'll try (cheaper) sponges from one of the two major US electronics component suppliers.