1、Good Accuracy: Our guitar notched straight edge has a good accuracy, which can ensure you have enough certainty to measure during the use. 2、Notched on Both Sides: Made of 5mm or 0.19in aluminum, notched on both sides, one for 25.5in and the other for 24.75in. Accurate cutting and accuracy machined to less than 0.02mm. For 21 to 24 frets. 3、Inspection Function: This guitar notched straight edge is the easiest way to check the flatness of the fingerboard, and it is very easy for newbies to get started. 4、Easy Storage: This guitar notched straight edge is very easy to store and is a good tool for luthiers or enthusiasts who like to manipulate the fingerboard. 5、Safe and Sturdy: This guitar notched straight edge is made of superb craftsmanship, safe and sturdy, harmless to human body, and can be used with confidence.