D'Addario EXPPBB170S Phosphor Bronze Coated Acoustic Bass Strings, Short Scale, 45-100 EXP Coated phosphor bronze for warm, bright, well balanced acoustic tone and 4 times more life Environmentally friendly, corrosion resistant packaging for strings that are always fresh Made in the U.S.A. for the highest quality and performance String Gauges: Phosphor Bronze Wound .045 .065, .080, .100