Item Type: Guitar Strings Product Material: Carbon Steel Inner Core + Colorful Nickel-containing Copper Alloy 1This guitar set is suitable for guitar and electric bass, and will promises athe stable playing and excellent sound quality. 2All the guitar strings are wrapped with colourful nickel-containing copper alloy wire, which will protect your hands from being hurt. 3The anti-rust surface adds extra durability, while the reinforced carbon steel core is very tough for long-term use. 4The colourful design will largely help beginners in memorizing and practice, and makes the guitar more beautiful as well. 5The package has perfectly sealed the strings, which is also moisture-proof and rust-proof packaging.4 x Guitar String