Got these to replace the stock tuners on a HB 457FFB (bought this pack, plus a single R1 as needed for my lefty model). As this was my first ever "DIY" change to a guitar, I was a little wary of ZERO instructions included in the packaging, even something as basic as to show how the tuning nut goes into the base housing through the tuning holes on the headstock. It's a small thing, but would be super helpful for DIY novices. In any case, taking the stock tuners out made it clear how the new ones would fit in, so I didn't have a problem.
Once installed, the locks hold really well; tuning stability is perfect. I have 3 different guitars and 2 different basses that I play for different projects, and sometimes won't come back to a guitar until 4-5 days have passed; came back to my 457, and it barely needed any adjustment. Overall, a perfect kit for someone's starter DIY projects, and excellent quality. Might just get more sets to replace the existing tuners on my other guitars as well!