Ernie Ball Slinky Flatwound Bass Strings combine the smooth feel of traditional flats and the modern power of Cobalts. Featuring a SuperBright Cobalt Ribbon wrap, Cobalt Underwraps and optimal hex-core to wrap ratio, the new Flatwound Bass strings are the first flat that actually feels like a flat and sounds like a round. Gauges .045 .065 .080 .100 .130