Material: Stainless steel With scale for string height, for ridge saddle slot depth and for nuts saddles and polepieces guide for setting the action on any stringed instrument It's faster to use than any ruler, and stays parallel to the fingerboard—much easier than trying to hold a ruler perpendicular to a rounded fret The gauge features a progressive string height scale: simply slide it across the frets and read the measurement under the string With conversion chart of string action at 12th fret up to guitar standard printed on one side Long lasting etched printing, the printing will not wear off from long use Great pocket-sized ruler made of durable stainless steel Suitable for string instruments such as guitar, bass, mandolin, banjo, etc Scale range for string height: 0.01-0.14inch / 0.25-3.50mm Scale range for bridge saddle slot depth: 0-0.875inch / 0-20mm Scale range for nuts saddles and polepieces: 0-0.48inch / 0-20mm Ruler size: 8.9cmx5.1cm/3.5''x2.0''(LxW) Quantity: 1 Pc With scale for string height, for ridge saddle slot depth and for nuts saddles and polepieces guide for setting the action on any stringed instrument It's faster to use than any ruler, and stays parallel to the fingerboard—much easier than trying to hold a ruler perpendicular to a rounded fret The gauge features a progressive string height scale: simply slide it across the frets and read the measurement under the string