Martin Retro Acoustic Guitar Strings, 6 String Set, Tony Rice's Signature Martin Sound, Monel Nickel, Bluegrass Gauge (E .013, B .016, G .026, D .034, A .044, E .056), Tension 184.9, Martin Item MTR13.

Retro strings offer a uniquely mellow, yet crisp, sound that allows your guitar's natural tone woods to be heard, not overshadowed. They are crafted with Monel, a solid Nickel/Copper wrap wire - not nickel-plated - meaning there is no chance for defects in the plating to allow for corrosion. Instead, Martin’s proprietary wrap wire is naturally corrosion resistant and it is incredibly strong. A sophisticated winding process is employed in the making of the Retro String that controls the coupling between the core and wrap wire to maximize intonation. With Martin Retros, you get one tough set of strings that will last a long time and give you true, consistent tone that sounds like nothing else on the market.