Flabellum

A flabellum (plural flabella), in Catholic liturgical use, is a fan made of metal, leather, silk, parchment or feathers, intended to keep away insects from the consecrated Body and Blood of Christ and from the priest, as well as to show honour. The ceremonial use of such fans dates back to ancient Egypt, and an example was found in the tomb of Tutankhamun. A flabellum is also a fan-shaped structure on the fifth legs of horseshoe crabs (Xiphosura).