Acoustic Guitar String, Extra High Tension, Finish: Tie-End, Coated, Standard Tuning, Nylon Wrapped with Silver Copper, Extended Life Treatment on Each String, Preserves the Natural Tone and Feel of Uncoated Strings , Patented Composite Bass and ProArte Treble, Dynamic Response with Long-Lasting Performance, Lasts at Least 4 Times Than Traditional Uncoated Strings, Resealable Internal Packaging for Easy Opening and Storage of Unused Strings, Gauges: .0290, .0332, . 0415, .0300, .0360, .0470, ideal for jazz and classical.