This is a DC plug (3.5x1.35mm). You can find this cable at digitec: InLine USB DC power adapter cable InLine USB DC power adapter cable (2 m) Best regards

Under dental care, Galaxus only has "brush head" or "electric toothbrush" as categories. Since this device "electrically" "cleans" your teeth, it was probably easier to define this as a toothbrush. Where would you classify it then? :)