Gauges 45-65-80-100. D"Addario EXL170TP Bass Guitar Strings feature round-wound, nickel-plated steel wrap wire for bright, true sound without premature fret wear. D"Addario is the world"s largest manufacturer of strings for musical instruments. Many top guitarists won"t play any other brand. Regardless of your playing style, D"Addario has a set of strings that"s right for your bass guitar.