Ernie Ball Coated Bass Strings Ernie Ball Coated Hybrid Slinky Bass Strings - 45-105 Gauge With Enamel Coating Coated Bass Strings Extended Life Optimal Core to Wrap Ratio - Comfortable Tension and Playability , Number of strings: 4. SuperBright Cobalt Ribbon - Superior Sheen and Feel Ernie Ball Slinky Flatwound Bass Strings bring together the smooth feel of traditional flats with the modern power of cobalt. Cobalt, a metal that Ernie Ball introduced to the electric string world, displays a very strong attraction to the magenets in guitar and bass pickups Optimized hex-core/wrap ratio Ernie Ball 2813 Hybrid Slinky Flatwound Electric Bass Strings (45 The world's first and only cobalt Flat wound bass string! Can I self-collect my item(s)? Of course! Ernie Ball Slinky Cobalt Flatwound Bass Strings combine the smooth feel of traditional flats and the power of Cobalt. Featuring a SuperBright Cobalt ribbon... Winding Material : Iron/Cobalt Scale Length : Long SuperBright Cobalt ribbon wrap, Cobalt under-wrap