Sometimes you have to start with S I M P L E then add to it...Reliable. Easy to use. Lethal ( within context ).
I have say though, from an N-Gin-Ear, I would have expected some other material other than rubber tubing.
They works wonders on elaborately etched front window panes of a certain small town insurance company as well. Also outside the statute of limitations.Marbles are great for Dirty Tricks and payback. They shatter on impact with a hard surface and obliterate any evidence of wrong doing. They work wonders on car windows....I won't elaborate but the statute of limitation has expired on that one.
Stat of limitaions, or the fifth, depending on where it landed....Golf balls really go far when you put 150psi behind them.