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Martin M550 Phosphor Bronze Acoustic Guitar Strings are made with a unique composition to give brilliance, clarity, and longevity of sound. The Phosphor Bronze winding alloy is ideally suited for making strings that have deep, rich basses and clear, bright trebles.


Martin Strings are high-quality strings for daily use. Core and wrap wires must meet strict requirements to make the grade. Martin Strings are wound to precise specifications.