HI-DEF NEON MULTI-COLOR Colored Acoustic Guitar Strings: Custom Light 11-50 Designed to give your stage presence a little extra pop, especially under UV black lighting They feature a hexagonal core wire and a silver-plated copper wrap wire on the wound strings All strings include the neon colored K3 coating, delivering longevity, more projection, fewer unwanted overtones, plus enhanced clarity and articulation 11, 15, 22, 30, 40, 50 String Material Type: Nickel