These are great little workout tools for the fingers. Whether you are warming up to play an musical instrument or if you just want to build strength. I use these very often before warmup, it reduces the amount of time I need for warmup on the instrument which is great because playing typical warmups is boring on any instrument. Use these gripers before and you're good to go almost immideately when you start playing your instrument.
The quality is good, I've had this for over seven years and the springs have basically the same resistance they had when it was new.