EXP75, D'Addario's heaviest gauge coated 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 EXPs are the most natural-sounding, longest-lasting coated strings available. EXP Coated Technology starts with the highest quality wrap wire materials, precision drawn and micro-coated on our advanced proprietary machinery. Strings are then wound normally, delivering tone and feel identical to D'Addario's world renowned mandolin strings, with a minimum of 4 times more life. You won't believe they are coated!