These are Ernie's "Regular Slinky" strings. Made from nickel plated steel wire wrapped around tin plated hex shaped steel core wire. By far the most popular, produces well balanced all around good sound. Ernie Ball Regular Slinky 7-Strings Electric Guitar String 1056 Features: Type: Electric, 7-String Gauge: .010 .013 .017 .026 .036 .046 .056 Balanced sound Tin-plated hex steel core Nickel-plated steel wrap Ernie Ball nickel wound strings make your electric guitar sound and play great!