S.O.S improves the intonation at each fret and easy installation to your instruments.
We only insert the S.O.S next to the nut between the fingerboard and the strings.
We develop S.O.S. to fit most of major instruments like dreadnought size guitars or classic, etc.
It is designed and based on MTS theory (Patent no. 4383272) and made in Japan.
for acoustic guitars , fitting scale : 643-650mm

for classic guitars, fitting scale: 640-650mm

for electric guitars , fitting scale : 628-650mm

for soprano ukulele, fitting scale : 340-350mm

for concert ukulele, fitting scale : 380-390mm

How can it improve the sound of your guitar?