Ernie Ball 2815EB Extra Slinky Flatwound Bass Strings 40-95Ernie Ball Slinky Flatwound Bass Strings combine the smooth feel of traditional flats and the power of Cobalt. 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 . 040, . 060, . 070, . 095