On this parts fiche the Washer is the most specified component.
A sample from the products for the Flasher Light include: Screw,lens Fitting, Washer, Rr. Flasher Light Assy., Lens, Flasher.
The most reasonably priced component used on the Dt50rsm 2007 14p1 Slovenia 1f13c-300e1 Flasher Light is the Nut.