I ordered 3 Jet Tool Locks and ended up getting a few more than I intended...
so I have some to sell. By themselves they are somewhat effective, but add a block of wood like in the photo below and they are 100% effective. When I ordered them, they were $7.99 plus S&H.You can have them for $4 each plus the cheapest S&H I can get (USPS), can't be more than a few $$, they are small and light.
I have to imagine that other tools can take advantage of these. You can set the combo to what every you want it to be. They would also appear to be useful for many other purposes.
Mike