Features: 
Precise and clear calibration.Made of high strength stainless steel, durable.
The 12th fret string-distance has engraved on and clearly to read, which provides you with a set of standard data.
They include: electric guitar, acoustic guitar and bass, Two units comparing groups are visible including inches and millimeter.
Suitable for guitar, bass, ukulele, banjo, mandolin and other stringed instruments.
Multifunctional measuring tools,string-distance,bridge saddle height and depth,fret groove depth.string-distance of electric guitar pickup.
It's the direction guide for your guitar repairing.A tool must have for every serious player.
pocket-size body, you can take it anywhere. Say goodbye to your heavy caliper.

Description:
You may be anxious to know why your guitar handle always not good enough. Here's a parameter with the highest impact: string-fret distance.For most performers, ultra-low string-fret distance makes playing easier.
We just need to focus on the string distance of 1st fret and 12th fret.
The string distance of 1st FRET is as low as possible, and 12th fret is suitable to keep below 4mm. If can reduce it to 2.5mm or less, the feeling will be very comfortable.
How to measure string-fret distance?
This string action ruler can help you get these parameters accurately. There are ways to use it in the picture.

How to adjust it?
Method 1: The bending of neck can be adjusted by Allen wrench.
Advantages: Simple, time-saving and labor-saving, quick results.
Disadvantage: We try to keep the neck of the guitar straight, which is very important for the life of the guitar. Bending neck long time may cause irreparable consequences.
For hands-on players, we recommend the method as follow:
Method 2: Adjust the height of bridge. It can be accomplished by polishing bridge nuts. The string distance of 12 th FRET will be reduced by 1 mm for every 2 mm reduction of bridge height.
Advantages: Guitar is alive, it must like this way better, because it feels very comfortable.
Disadvantage: Heavy workload, time-consuming and laborious.

 
 Specifications: 
  Material: Stainless steel
  Ruler size: 8.9*5.1cm
  Package weight: 23g

 Package Included: 
 1 X String Action Ruler