Everly B-52 Medium Bass Strings, .045-.105 Medium String Gauge: Wound .045, .065, .085, .105 4 strings Unlike standard electric strings, B-52 Rockers are made of Alloy-52, a unique combination of 48% iron and 52% nickel. With the higher iron content than traditional nickel strings, Alloy-52 is much more tarnish resistant and durable than nickel. The best part about alloy-52 is its highly magnetic giving you brighter tone with better punch and sustain.