The GraphTech Black TUSQ XL Nut is a great option to upgrade the nut on your 4-string bass.

It is pre-slotted for a quick and simple installation.

Flat bottom.

Length  1.496”  /  38.0mm
Thickness  0.238”  /  6.05mm 
Height  0.364”  /  9.25mm 
String Spacing  1.141”  /  28.99mm