Acoustic strings crafted with a blend of 80% copper & 20% zinc enhances treble and gives your guitar a brighter, clearer tone. Paired with Cleartone's patented EMP treatment, 80/20 strings will not only outlast any string you've ever had, but also increase your guitar’s volume and sustain by as much as 36% & 48% respectively. Tested under labratory conditions. Satisfaction guaranteed. What are you waiting for?