Each of the four compartments of the canopic chest held a miniature coffin. Covered in linen, they stood upright in their cylindrical compartments. Each was almost glued to the bottom owing to the hardening of the unguents that had been poured in as part of the ritual. It was the duty of the goddess Nepthys, whose name is inscribed on the front, to protect the lungs of Tutankhamun, which were placed inside, after first being preserved. The figure, fashioned of solid beaten gold, contains inlays of colored glass and semiprecious stones. It is very close in design to the second coffin in which Tutankhamun was buried; in fact, it is almost a miniature version.

The inscription written in the panel on the front are words spoken by the goddess Nepthys. She states that she will protect Hapy; Hapy means the lungs with which the god Hapy is associated. The figure is mummiform, and across the upper part are the protective wings of two vultures, one of which, however, has the head of a cobra. The two represent the goddesses of Upper and Lower Egypt.

The inside of the canopic coffin is completely engraved. The upper part, which corresponds to the lid of the coffin, shows Nepthys with outstretched wings. The remainder of the top and the entire bottom is inscribed with hieroglyphs. The cartouches show indications that the name of Tutankhamun was not original and that it has replaced the name of his elder brother, Smenkhkare. In fact, the face portrayed here is quite distinct from that shown on other pieces.