Everly B-52 Electric Strings .0092-.042 Ultra Light/9209 Gauges 9-42, 52% iron/48% nickel, extremely durable and responsive Resists tarnish, awesome resonance 52% iron mixed with 48% nickel is the formula for Alloy-52, the material used in the Everly B-52 Rockers Alloy Extra Light Guitar Strings This magnetically active alloy makes for an extremely durable, highly responsive electric guitar string with awesome resonance characteristics It resists tarnish up to 3 times over its nickel-plated steel predecessor and delivers more sustain and overtones