UltraSonic stainless steel bass strings are precision wound from premium grade, specially selected alloy materials. Our unique formula results in a very open, musical sounding string with exceptional response, optimum sustain, brilliant tone, and extended life. The rich harmonic content of these strings articulates the detail of the instrument's voice by providing a solid bottom, great mids, and superior top end. The special core-to-winding ratio ensures each UltraSonic string set is properly tensioned for perfect balance and feel. Brighter, long-lasting tone and a favorite of pro players worldwide!