Thomastik-Infeld JF345 Jazz Nickel Flat Wound Round Core 5-String Bass Guitar Stringsstar rating 51954bassmanJune 1, 2011Favorite of all flatwounds I have ever tied. Very low tension, rich, syrupy sound. Works great on a fretless in an acoustic setting. The only con is the low tension gets too floppy playing outdoors in high heat, strings turn to pasta.