The LK81080 is a factory-new aircraft washer supplied with traceable paperwork. As a washer, its primary role is to distribute clamp load, protect mating surfaces, and set correct stack height when used with bolts, screws, or nuts. Washers help prevent loosening, reduce indentation in soft part,s and keep fastener preload stable under vibration. https://gfa.aero/aviation-parts/expendables/LK81080