Gauges 13-17-26-36-46-56. Different guitars respond differently to different alloys. Some sound better with ronze, some sound better with Dean Markley PhosBronze. If you want a lot of power and punch, with lots of midrange and highs, or your guitar's top needs extra punch to project, try a couple of different gauges to find just the right gauge for your guitar. PhosBronze is powerful and very bright while still having a smooth low end. Dean Markley PhosBronze strings come factory equipped on many acoustic guitars.