BowZo - Bowing Practice Aid

I use this during lessons to show students how easily they stray from the sounding point. They usually hate it, but it makes a good point. I don't have them purchase their own. I think it's better just to use it ever now and then in a lesson.

Horrible! Completely changes the tone of the violin.

I bought this directly from young musicians and just received it. I tried it out and it is not useful at all. The bow constantly rubs against it and mutes the sound. Although i paid less than what it costs from Amazon, it still was not worth the money.