These authentic strings are crafted just like they were in the "50s. Vintage Reissue strings are made from the purest nickel wrap wire and finest quality core wire. Vintage Reissue strings are wound at the right speed under optimal conditions to ensure long-lasting quality and true vintage tone. Just like Gibson instruments, authentic Gibson strings are American made, world played. And, like our instruments, our genuine strings utilize strict quality control methods to ensure tone, durability and consistency. All Gibson strings feature specs absolutely unique to Gibson and are factory sealed to guarantee freshness in every set.