Ernie Ball Aluminium Bronze Acoustic Guitar String features more projection and clarity than traditional bronze strings, while also providing improved corrosion resistance. Aluminium Bronze Acoustic strings are made with maraging steel hex cores and aluminium bronze wrap wire which provide more pronounced lows coupled with crisp brilliant highs. Made from a blend of copper and aluminium specifically tailored for acoustic guitar strings. Extra Light gauge .010, .014, .020w, .028, .040, .050.