EJ75, D'Addario's heaviest gauge mandolin set, was designed in cooperation with Ronnie McCoury, who's hard driving, percussive style requires increased tension for maximum volume. Loopend construction for universal fit. D'Addario mandolin strings are trusted by legends like David Grisman, Ricky Skaggs, Ronnie McCoury, Doyle Lawson, Rhonda Vincent, Mike Marshall, Adam Steffey, and more, for their natural acoustic tone and reliable performance. They are made from the highest quality plain steel, stainless steel, nickel plated steel and phosphor bronze and are available in a wide variety of gauges.