Phosphor Bronze acoustic bass strings give you the sweet tone and easy feel you want when playing unplugged. With their beautiful sonic balance and tonal warmth, D’Addario Phosphor Bronze have become the standard in acoustic bass strings. Precision wound with phosphor bronze wrap wire over a high carbon steel core, D'Addario's Phosphor Bronze acoustic bass strings provide unparalleled versatility suitable for most acoustic styles. Made for 5-string acoustic basses, this 45-130 Regular Light 5-string set fits most standard sized acoustic basses.