Safety paper fastener

Another kind of office supplies that I often use at the office is a safety paper fastener.  It is a device made of thin, soft metal, with a round head and a flat, split shank, which is spread after insertion in a hole in a stack of pages, in much the same way as a cotter pin or a split rivet.
Any similar stationery fastening device as to say. There are variety of designs available in the office supplies store on paper fasteners. Some are made of plastics, brass or silver coated.  this is very useful every time I have important reports to file in one  folder.