This pack of Ernie Ball 2817 Power Slinky Flatwound Short Scale strings will kit out any short scale electric or steel-string acoustic and electro-acoustic bass with the warm, round sound and smooth playing feel of flat winding. If you are installing these strings on an acoustic bass, then double check that the build of your instrument can handle it and, whether electric or acoustic, that the scale length is no longer than 30 inches. Part of the Bass Slinky Flatwound range, these strings have been made of cobalt, which doesn't just boost the comfort and sonic warmth but adds more depth and definition. This pack includes gauges .055 to .110.