I bought these schaller tuners as an upgrade for my Mexican jazz bass. Having never previously purchased schaller, I was relying on reviews I had read elsewhere. They come in a well packaged box with ferrules and screws and as soon as I turned the elephant ear, I could tell.that these tuners were of superior quality. I had already worked out that the hole spacing on the mounting plate was slightly different to the original machine heads but I was able to plug the old holes with cocktail sticks and wood glue which, when rubbed down, was almost invisible to the naked eye. My impression of the schallers increased once again when I removed the strings on my bass as the stock ones were considerably slacker and actually rattled. I had to use the original ferrules as the schaller ones were slightly smaller than the holes on the headstock. Once fitted, they looked amazing with the engraved logo and they have stayed in tune ever since. A top quality upgrade and money well spent in my opinion. The only other thing to add is that they are no lighter than the stock tuners, but the bass was well balanced to begin with so it wasn't an issue. Perhaps if your looking to correct some neckdive, these are not the right tuners for you. Once again, excellent quality for the price.