GHS Strings BNR-M Burnished Nickel Rockers, Polished Pure Nickel Electric Guitar Strings, Medium (.011-.050) Model: BNR-M Featuring the air-tight Fresh Pack & NitroPack singles, guaranteed fresh from the factory! Roundwound Lightly Polished Pure Nickel on a Hex Core Pure nickel wraps for a warm vintage tone. Medium Gauge: 011-014-018-028-038-050