These super-light electric guitar strings use nickel-plated steel with Elixir's OPTIWEB coating, in gauges .009, .011, .016, .024, .032, and .042. The OPTIWEB coating is designed to feel and sound like an uncoated string, with a crisp tone and natural grip, while retaining Elixir's long tone life. As with all Elixir strings, the entire string is coated to keep grime out of the windings.