The tuners in my Stagg bass had poorly machined worm screws that ate up the gears because the screw is steel and the gear is softer brass. The new tuners have precisely machined screws, I checked with a loupe. The gears are better, too, at first sight they look the same as Stagg but with the loupe the teeth in the gears are better cut with a smoother finish, the Stagg gears had machining marks.
The machines came in cardboard box with two other items but the tuners' package was torn and they moved around inside the box, making a noise that worried me a bit when I received it. Nothing was damaged because the two other things were not fragile, and the chrome on the tuners is so hard they won't scratch easily.
However a double plastic bag shouldn't be torn, if delicate things had been present in that box they could have been damaged.
While the tuners were removed I reshaped the headstock, so it's a bit smaller; and the Harley Benton parts are also a little smaller by chance, so they're a better match for the resculpted headstock. It's also a detail you see only with a loupe but the mounting screws have a shape that allows an improved centering in the frame's holes. In case you haven't drilled perfectly the Stagg screws don't allow a margin because the top of their threaded shaft is conical.
But the screws delivered with the Harley tuners are straight so they self-adjust if the frame holes are not perfectly centered. It's a small thing but it makes the assembly easier. I had to plug the Stagg tuners' holes and drill new ones so this is not a luxury, when you drill sixteen holes there's a chance one or two will be a tad off-center.
The tuners are lubricated with a good, thick viscous oïl but only between the worm and the gear, other moving parts needed extra oïl. Once installed they are firm and fluid and have no play at all. You must always tune up for stability but the tuners are accurate enough that you could tune down.
Setting the intonation was not a problem thanks to that accuracy. After a couple weeks I checked the gears with my loupe, and they show no denting, no scratching, no wearing down of the chrome skin, nothing, just the shiny oiled surface.
Since those who reviewed these several years ago never edited their reviews to complain I trust they will last for very long.
Edit: I bought a second set for a Classic Vibe bass, and they work fine, just the same. The slight roughness I felt when they were brand new vanished after oiling them and breaking them in. They don't have the instant and ultra-fine responsiveness of Grover machines when tuning up or down, but very close to it, and they are so affordable.
Edit of august 2025: I installed a third set on a bass, and the comments are the same; quality is very consistent.
