Physically, SCP-513 is an unremarkable, rusty cowbell. Any noise produced by SCP-513 immediately induces strong anxiety in all sentient beings who hear it, regardless of their previous mental status.
*A small rusty cowbell falls out of a vent on the ceiling and lands on the ground next to you. it looks like a unremarkable, rusty cowbell. No marks or engravings are visible on its surface due to the large amount of corrosion.*