Honestly they are way too expensive for what they offer. I bought them to put inside the f-hole of a jazz box. Wheels turn very very easily and are quite close together, so very easy to mistakenly turn the wrong one when you reach for the other. Tone wheel works poorly: no change between 3 and 10, all change between 0 and 3. The knob itself does not come with any means of attaching itself, not even screw holes, so you just have to figure out by yourself how to do it, trying to avoid damaging the exposed components. Even the schematics provided seemed outdated. Do not recommend, unfortunately