Complete replacement Victoria ScT brake system kit - Includes - Elastic cord and Black knob.
There are two types of Victoria brake systems. Original Victoria's were delivered with a cotton cord, and Spring system attached to a black knob to twist and adjust brake tension.

Later the knob was fastened with a screw to prevent it from falling out.
Several years after production began, Louët switched to an elastic cord for the brake to replace cotton cord and spring. This required bobbins to have a U shaped groove instead of a V shaped groove. If your bobbin has a V shaped groove, the elastic will create a whirring sound. You can minimize this by sanding the groove in your bobbin, or replace your bobbins.