The new D'Addario XTB45100 strings for Bass have a microscopically thin, moisture-repellent coating on all strings that does not affect the tone or feel. The new, improved coating process preserves the feel of fresh strings that last at least three times longer. Made from "High Carbon New York Steel", the XT strings achieve greater tensile strength and tuning stability.
From the production of the base material to the coating and the winding of the strings, D'Addarrio produces everything in its own factory.
Fender Bass Strings Flatwound 050-100 
D'Addario 4er Bass NYXL 45-100 45-65-80-100, NYXL45100
DR Hi-Beams 4-String Bass Medium Short Scale 45-105
D'Addario 4er Bass NYXL 45-105 45-65-85-105, NYXL45105
Ernie Ball EB2734 45-100 Cobalt Super Slinky