Replacement for any large kidney-styled machine heads. Very smooth tuning pegs, very precise. Sturdy and cheap.
One problem I had is that the previous machine heads weren't precisely made, so the new Klusons' screws didn't fit exactly in the previously drilled holes. But, they were put in a cheap guitar, so I don't consider that a flaw.
I bought these to replace the stock kidney Grovers on my Gibson Midtown Custom. The stock tuners would never keep the strings in tune, so they had to go. I find these replacement tuners from Kluson of better quality, as they are locking tuners. Additionally, the feel is better - they're softer and easier to use - definitely better than the Grovers.