Historic stainless flatwound guitar strings in gauges 13-17-26w-36-46-56. Great for jazz, but also used for many other styles of music.
Benefits of Stainless Flatwound Guitar Strings:
-Consistent tone over the life of the strings
-Less Fret wear
-Smooth surface causes less "squeaking" and easier on fingers
-Last longer than round wound strings, trade off in price.