Gauges 10-14-24-30-39-48, 10-14-09-12-18-28. Rare Phosphor Bronze Acoustic Strings are a departure from the standard, good-quality bronze string currently available--not necessarily better, but possessing a new, different, and stronger voice. Hand-carved archtops, dreadnoughts, and good steel string acoustic guitars of rosewood, maple, and mahogany benefit from a distinct improvement in tone, depth, and sustain with a fatter, louder sound and a deeper bottom.