.010 / .013 / .017 / .026 / .036 / .046 ProSteels round wound regular light ProSteels are the brightest and most magnetic guitar strings from D'Addario. A special alloy ensures harmonically rich, brilliant highs as well as increased crunch and sustain. Each winding is precisely wrapped around a hexagonal core, with exclusive computer-controlled machines monitoring the winding speed and tension. The result is strings with precise intonation and unmatched consistency, set after set.