Stainless steel and soft rubber, which is lightweight and durable. It can roll smoothly and will not damage your guitar or performance Adjustable guitar capo can roll the capo seamlessly to make the tuning stay stable and won't pinch the sound out of tune. just move the roller from fret to fret by your thumb, a different change of tune would produce. These rolling capo can work well with standard 4 to 6 string guitars, it's suitable for most string instruments like folk classic acoustic electric guitars, ukuleles, mandolins and banjos, a perfect choices for personal use or gift for your families or friends who like playing the guitar or other instruments. With the appropriate size and design, the sliding guitar capo can be scrolled up and down with one hand without the trouble of resetting, and it can be easily changed between frames. Easy to install and remove, store it on the nut of the guitar when not in useeach package include 2 pack guitar rolling capo.