Description: Material: T shped radius ruler and string action gauge ruler set, made of stainless steel and abs. providing you with a reliable tool that stands up to frequent use.Clear Scale: The ruler with clear and complete scale for accurate measurement. It's sturdy enough to withstand frequent use.Measurement: Guitar luthier tools can be used to measure string height, string distance, bridge height, etc.Wide Application:Guitar measuring tool is suitable for measuring stringed instruments such as electric guitars, acoustic guitars, electric basses, ukuleles etc.,Package Includes: 9 piece radius ruler and1 pieces string action gauge, ideal gift for friends. Size Chart: String Action Gauge Ruler:8.9cmx5.1cm/3.50inchx2.01inchUnderstring Radius Gauge :7cmx6.5cm/2.76inchx2.56inch Package Includes: 9Understring Radius Gauge1 String Action Gauge Ruler Note: Please allow slightly errors due to manual measurement and different monitors. SZRH A-F9Pcs Understring Radius Gauge