Ordered one of these to put in some string leeches and was disappointed. Directions say to use a bow press to avoid damaging strings, whereas the description says it isn't necessary. I had to twist my string several times and try to put this fat piece of metal between some very unforgiving string. Huge pain in the but and ended up fraying a little bit of string. Only use this if you have a bow press, not worth damaging strings and paying more for them than a $50 bow press that can easily get this minor job done.
It does what it is supposed to do. Easy to separate the bow string and easily holds it while you work. No complaints here. Seriously, give this little tool a try.