ZB-13 Unslotted Replacement Nut for Classical Guitars

I m impressed with this. Easy to install. I m not a luthiar but I have refretted a few guitars and made some nuts and saddles. This is a pretty incredible system. I was going to cut a new nut for an acoustic guitar I just bought. I tested it and it was not sliding perfectly through the nut even though there was no ping while tuning. The way I test a nut is to strike a note then smack the string between the nut and the machine heads. behind the nut I put a tuner on the head stock so I can watch the note go up and come back. It simulates a good bend and you can watch the quality of the nut you have on the guitar. Most guitars will stick at about 6 to 10 cents above the tuned note unless you have a really well cut nut. At least the wound strings will....steel strings will usually drop back to the tuned note if the nut is decent . The nut I had on this guitar was pretty good....no pings while tuning yet it would still catch occasionally which effected tuning.