Pyramid Charango Saiten Set Nylon

2 identical (e' e') for the third pair, normally for a charango is needed (e' e") to get the traditional sound for a charango and also usefull for changing to another charango tuning. So for a good charango set please ( e"e",a'a',e"e',c"c" and g'g') and better with 1 extra (e"). So the charango will sound how is it suppose to sound. Otherwise every charango player will ask you Why Is it not the third pair (e'e") included in the charango set? Right now i habe that Problem how to get one more (e") ,or change the second (e') that i dont need :/ , the Material quality ..excelent and sound very nice.thanks