The world’s first materially-tuned acoustic guitar strings. Similar to stereo equalization (EQ), each string is made from a different material that targets a specific frequency and, when played together, brings the whole set into perfect EQ balance. All Cleartone EQ's are made using only 100% US sourced premium alloys. It is not recommended using string cleaners on Cleartone Strings. Simply wipe down strings after use with a clean dry cloth.