Stonetone® patented and trademarked rock blocks are made of granite, and designed to enhance and strengthen the sound of your tremolo-equipped instrument across the entire audio spectrum. After installing a Stone Tone® Rock Block, the guitar’s clarity, sustain, and overall tone will be improved equally in all ranges of the fret board, the extraordinary results of this upgrade are indisputable. Made from Volcano Black Absolute Granite, the Stone Tone sustain block is one of the top tier upgrades for any Tremolo System, with a compression strength of 19,000 psi, a tension strength of 700 psi—the material these blocks are made of is the fourth densest on earth next to Diamond, Carbon and Quartz. The untampered material used to form these blocks has an inherent crystalline atomic structure which has ideal resonant qualities, and naturally increases sustain and amplitude on any  tremolo across all frequency ranges.