Nickel Bronze NB1356 acoustic strings are made to bring out the unique tonal characteristics of your guitar, allowing its natural voice to shine through. This distinctive string alloy creates a clear, focused sound, magnifying the sonic properties of the guitar’s wood. Made with a NY Steel core and nickel-plated phosphor bronze wrap wire, Nickel Bronze strings get you the most out of your guitar and your playing. 13-56 Medium gauge strings provides maximum volume and projection, with more tension and resistance.