Item Type: Guitar Fret Ruler Material: Aluminum and solid wood Size: Approx.46cm / 18.11in Package List 1 x Guitar Fret Ruler 1Professional Ruler: String action gauge ruler is perfect for checking the flatness of the neck of a guitar and the flatness of the board and post. 2High Adaptability: Guitar positioning ruler fits for acoustic guitar,classical guitar,ukulele, electric guitar with 22 frets necks. 3Convenient to Use:This guitar fingerboard positioning ruler with grooves has a smooth surface that won't scratch your guitar and is easy to use. 4Wide Application: These guitar fret ruler is given gift to guitar technicians and guitarists, let them maintain and repair instruments in a short time. 5Reliable Material: Guitar repairing positioning ruler is made of aluminum and solid wood, which is durable for maintenance and repair.