Jahn Diskant Tuning Wedge, Plastic

I've used it a few times for tuning the occasional out-of-tune string on my upright Kawai, but preferred the rubber wedges over this Diskant tuning wedge. As this is plastic, it slips easily and can sometimes get lost at the bottom of your upright, but if you have a normal (concert) piano, you wont have this issues. Gave it 4 stars total because if the spring was a bit stronger, it would hold the strings more firmly. I need to say that I am an occasional amateur tuner for personal purposes only, I tune my piano ever so rarely if one string gets a bit out of tune. Of course, once or twice a year I get a pro to do the proper job.