Bought these to replace a set on a Jackson Five String, was advised they are the same as those fitted by the factory, completely accurate. I would even say they feel slightly better, although more likely the olds ones needed a change far sooner, but the cost put me off. I should have done it sooner, these strings are fantastic value, have used Flatwounds from the same range, also outstanding. If you look online at the forums, most suggest Fender make the majority of strings sold under other brand names. I can’t confirm this but will say they are as good as strings at 50% greater cost.