Schaller SCH12130400 4 Strings Electric Bass Bridge (Black Chrome)Patented 4 string bass bridge, analog to 3D 6. The roller bridge saddles reliably minimize string breakage while maintaining intonation and tuning stability. Specifications 3 dimensional adjustment of string height, intonation and string spacing (with roller bridge saddles). The individual string intonation is set by adjusting the string saddles. Heavy and precise construction for extra long sustain. Complete with 3mm or 4mm spacer. The guitar or bass