An aegis is a broad collar topped by the head of a deity, in this case the lioness godess Tefnut crowned with a solar disk and uraeus. Amulets of this type were intended to offer protection to the wearer and avert potential dangers.
From Giza, G 7639 D, pit. Feb. 16, 1925: Excavated by the Harvard University–Museum of Fine Arts Expedition; assigned to the MFA by the government of Egypt.
Harvard University—Boston Museum of Fine Arts Expedition