Thomastik Spirocore Bass strings have been a long time favorite for jazz and bluegrass players. They have a robust pizzicato sound with a long sustain. They also are durable and long lasting with proper care. Some Orchestral players also really love these as a set or just to combine the very powerful E and A string with a G and D from another set, like Belcanto or Flexocore Deluxe. These strings will be shipped as medium gauge, but weich or stark gauges are available upon request.