SWING BASS 66 (Stainless Steel or Nickel Roundwound). The most popular Roundwound bass string ever. Rotosound was the first string company to produce this kind of string. Introduced in 1962 it changed the sound of the instrument instantly. The favourite string of many players including Billy Sheehan, John Paul Jones and Geddy Lee. Available in all popular gauges and scale lengths. The stainless steel used to produce these strings is unique and nickel free, coupled with a highly secretive manufacturing process.