SINCE 2010



Digital Action Gauge

Digital Action Gauge is Trademark or Registered Trademark in Japan.

With this device you can measure the Action of the strings and the neck Relief with no need of anything else. Very useful to check the set up or save it before taking any action on your instrument. With this tool you can also compare your set-up before and after a fret level. The Digital Action Gauge can also measure the Height of your frets and many other things! (0.01mm resolution and INCH conversion).


This is how to find the amount of neck relief by three points action measuring and a simple formula. By R.M.


More about the story of this device: Digital Action Gauge

Luthier tools


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  • Digital Action Gauge

    With this device you can measure the Action of the strings and the neck Relief with no need… Read More

    FRETBLADE™ is a special fret leveling tool that includes: Reference fret level, Adjustable relief, Single fret and spot level Read More

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Price list

REMINDER: to buy our tools please make sure to visit the How to buy page first. Thank you 

Prices are in USD

Final shipping price may vary depending on volume, weight and final destination of the order.

International shipping price is minimum $32. At the moment most destinations are covered by EMS which is quality service but it can be more expensive than certain other services that we have been using until a few years ago which aren't available at this time.

*There might be some lower prices for those Countries that still offer economy shipping services. Please let us know where you buy from so we can check the latest shipping options and prices for your Country.

RED is out of stock

RR Kit is accessory (sold only with a leveling tool)

R.M.KATANA for guitar $220 +Shipping  $32
R.M.KATANA for guitar Limited Edition 440mm $195 +Shipping  $32
R.M.KATANA for bass $255 +Shipping  $42
R.M.nanoKATANA *uke $145 +Shipping  Ask
R.M.BUZZ-Killer single fret and spot leveler  $80 +Shipping  Ask
R.M.LITE for guitar  $40 +Shipping  Ask
R.M.LITE for bass  $55 +Shipping  $38
Rocking File  $18 +Shipping  Ask
C-File --- --- ---
UNDERSTRING FLK mini  $59 +Shipping  Ask
RR Kit (reload/refinishing)  $38 Accessory  
LittleBone #400 grit  $20 +Shipping  Ask
LittleBone #150 grit  $24 +Shipping  Ask

LittleBone DoubleAngle #400 grit

 $28 +Shipping  Ask
LittleBone DoubleAngle #150 grit  $28 +Shipping  Ask

LittleBone DoubleGrit


 $28 +Shipping  Ask
LittleBone ice #320 grit  $28 +Shipping  Ask
LittleBone ice #150 grit  $28 +Shipping  Ask
LittleBone ice DoubleGrit  $42 +Shipping  Ask
LittleBone ice Special  $38 +Shipping  Ask
Digital Action Gauge  $42 +Shipping  Ask
FRET RAIL mini  $16 +Shipping  Ask
Feather File for nut   $20 +Shipping  Ask
BOOMERANG FRET FILE  $46 +Shipping Ask
TREM GUARDIAN  $38 +Shipping $15
DRAGONCLAW  $28 +Shipping Ask


About Rectify Master

RECTIFY Master focuses on research and development of innovative and quality luthier tools. Setting new standards since 2010. With over 30 year experience. Beware of imitation.

TOKYO, Japan

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