D'Addario ECG26 XL Chromes Flatwound Corde per chitarra elettrica Jazz Med 13-56
The 4 bottom strings are wound with a flat ribbon (rather than the usual round wire), which is then polished to make even smoother. Great for that classic jazz tone or rockabily twang. The thicknesses are 13, 17, 26w, 35, 45, 56.