Pros : The single hole is deceiving, I initially thought I would get a muddy color in my glass, quite the reverse, I have a beautiful swirled effect in a beautiful sheet that I can slump or a perfect circle. This is a handy tool to have in any glass makers tool box.
Cons : I have not found any yet. One practice and I got it perfectly right. My products look professional are orignal and I cannot find anything to call a con.