Sale is for 1 Single E string

Thomastik Infeld Red and Blue strings are relatively insensitive to
humidity changes, break in quickly, and have a relatively low tension. A
new synthetic, composite core gives Infeld Red and Blue strings a full
sound and a longer life span than other synthetic strings. The Infeld
strings are also responsive to different playing techniques. Red strings
have a darker tonal quality and Blue has a brighter tonality. Each
corresponding individual string, Red or Blue, has the same tension. This
allows the player to achieve tonal preference in a single string brand
without the headaches of uneven tension. Removeable ball on E string.