Zero Glide - ZS-3 Slotted Replacement Nut for Martin 3 Saddle The ZS-18 is for bass

The ZS-18 is for bass guitars

5mm Spacing

wound to the same specification as given to Trev Wilkinson by the creator of the humbucking pickup design

This is usually referred to as bowing or "bellying" of the soundboard - The JLD Bridge System has been designed to fix this problem

Zero Glide - ZS-3 Slotted Replacement Nut for Martin 3 Saddle The ZS-18 is for bassZero Glide ZS 3 Slotted Replacement Nut for Martin The Zero Glide Replacement Nut System borrows the "zero fret" concept to reduce string contact in the nut by up to 93%, increasing tuning stability, playability, and open string tone. It only takes a few minutes to install with absolutely no permanent alteration to your instrument. For Martin Style Guitar.