The unique, highly magnetic alloy in ProSteels delivers super-bright tone with magnified presence and attack. Made with a high carbon steel core and stainless steel wrap wire, ProSteels produce enhanced interaction with magnetic pickups, offering a palette of harmonically rich, brilliantly penetrating highs, combined with pronounced, tight-and-tough lows. This 43-127 Custom Light Top/Medium Bottom 5-String Tapered set is a D'Addario custom hybrid bass set optimized for PRS basses, with the unique gauge combination of .043 and .063 for the high strings with tapered low string gauges of .085, .107, and .127.