Rotosound ULTRAMAG Type 52 Alloy Electric Guitar Strings are made up of 52% nickel and 48% iron. This composition will accentuate the mids and lows over steel counterparts, allowing for more power, volume and sustain while maintaining tuning. Rotosound ULTRAMAG Type 52 Guitar Strings possess corrosion resistant properties to extend the life of the string and provide a unique tonal quality that will take your guitar and your sound to the next level. Rock it! (Yeah...) 11, 14, 18, 28w, 38w, 48w • MFSKU UM11 • UPC 686194011192