Medium GHS GBM Coated Boomers Electric Guitar Strings are made with roundwound nickel-plated steel. Designed for heavy metal, rock, country, blues, and pop styles, the dynamite alloy Boomers help you achieve a bright, long-lasting tone. A set of medium GBM Coated Boomers guitar strings range in gauge from 11 to 50.GHS String DesignGHS has made high-quality replacement strings since 1964 and GHS Boomers are their most popular electric guitar strings.The string specialists at GHS bring a craftsman-like approach to each aspect of guitar string design. From material selection to such intricate factors as core-to-cover ratio, winding direction, wire tension and alteration of the wire, GHS designs state-of-the-art strings that enhance the sound quality of all playing styles and instruments.