La Bella Lute String Set, 8 Courses There are 16 strings in twelve envelopes labeled as follows:; - - 1st Single: .017 TPN - 1 string; 2nd Unison: .023 TPN - 2 strings; 3rd Unison: .0265 TPN - 2 strings; 5th Octave: .018 AW - 2 strings; 6th Octave: .020 AW - 1 string; 7th Octave: .021 AW - 1 string; 8th Octave: .022 AW - 1 string; 4th Unison: .017 SPW - 2 strings; 5th Fundamental: .020 SPW - 1 string; 6th Fundamental: .025 SPW - 1 string; 7th Fundamental: .0295 SPW - 1 string; 8th Fundamental: .034 SPW - 1 string; - TPN= Trebl