The Planet Waves NS Capo is constructed with aircraft grade aluminum. It works on 6 or 12 string acoustic and electric guitars. You are assured of a buzz-free, in-tune performance with the Planet Waves NS Capo. It has a patented micrometer adjustment mechanism that lets the player dial in whatever tension they want for clear ringing notes, without putting excessive force in any position on the neck. This will help you from having to re-tune your guitar after use. Extremely durable, the Planet Waves NS Capo is actually very light, and wont add extra weight or obstruction to your instrument. It was designed in collaboration by product designer Ned Steinberger, Jim D'Addario and Planet Waves.