I wouldn't know. I'm not sure how much variance there is from year to year in the metal they source for string making. As material suppliers change or go out of business some products may change, I don't know if Pyramid has changed. I have a set of those Gibson flats. They are sort of like Labella, and some other Gibson sets were made by Maxima, who make a similar string to Pyramid. I'm just getting home from a gig where the Pyramids were surprisingly good sounding, especially considering I play roundwounds on my '77 MSB up until tonight. Today, I took off the Swing Bass 105-45, installed and intonated the Pyramids, loosened the truss rod, raised the action, and went straight to my gig.