This listing is for one set of Vintage La Bella Nylon Baritone Ukulele Strings No. 25. This set is sealed, but the front says - 1st and 2nd Plain Nylon and 3rd and 4th Wound Nylon - Recommended by Eddie Connors, Creator of the Baritone Ukulele. These are new and in sealed package. I don't know anything about strings. My dad owned a music store in the 70's and this is from his estate.