Phosphor Bronze Acoustic StringsBlackSmith acoustic guitar strings are made with the finest materials and manufactured using state-of-the-art automatic servo controlled winding equipment. USA made phosphor bronze and steel ensures a long lasting string with increased sustain and purer & warmer tone.Our proprietary computer controlled winding technology produces strings with a very consistent wrap surface and even tension, resulting in stable tuning, accurate intonation, and superior playability.Sub-Zero treated plain steel strings offer brilliant tone with a silky feel. With BlackSmith acoustic guitar strings, you will experience the perfect balance of consistency, tone, and playability. Vacuum Sealed in Patented Anti Kink Packaging Prevents Oxidation and String Damage.PB-1254 - BlackSmith's best selling Phosphor Bronze acoustic set, offering the ideal balance of tone and comfortable playability. Known for its warm tone with high end sparkle and well balanced feel.