This is the inner coffin of a woman called Tabakenkhonsu who lived and died during the 25th Dynasty around 2600 years ago. She was buried in the temple of Hatshepsut at Deir el Bahri, and I shared a photo of her bead shroud a few weeks ago.
She was buried in 3 coffins and you can see parts of them all in this photo. The outer one was rectangular and the other two are person shaped – you can see the lower part of the outer one with bedpost like corners at the far end, as well as the lower part of the middle one.
The inner one is displayed here with the lid as well as the base. On the foot end is a very typical decoration for this period – the deceased is shown as a mummy being carried by the Apis Bull towards the tomb.
These coffins were found at Deir el Bahri and are now in the Met Museum, acc. no. 96.4.3.
See it on my photo site: https://photos.talesfromthetwolands.org/picture.php?/1538/category/6