Mishnayos Oholos Perek 3 Mishnah 6

כזית מן המת פתחו בטפח – the corpse that is in the house and it has many openings, all the vessels that are placed in the cavity of the openings underneath the lintel/cross-piece of the opening from the outside, even though the openings are locked, and there is an interruption between the tent of the corpse and the tent of the vessels, all of them are impure. For the Sages decreed that defilement on a place which is the exit path of defilement that ultimately is of a corpse to exit there, and when we don’t know which path he will remove it, all of them are impure. But if there is an olive’s bulk from a corpse in the house and he intended to remove it through the window that has an opening of a handbreadth, he protects all of the locked openings since he knows the place that ultimately the defilement will leave in that path, but if it is entire corpse and he intended to remove it through the window that has four [handbreadths], he protects all of the locked openings for with the measure of four handbreadths, the Sages estimated that it is appropriate for the removal of the corpse.

אבל להוציא את הטומאה בפותח טפח – even a complete corpse, its defilement departs through the window all the time that it is open, and defiles the vessels that are in the house that are at its side if there is a window that is open a handbreadth.

גדול מכזית כמת – specifically like a pressed-in olive’s bulk, its opening is with a handbreadth. But more than an olive’s bulk, its law as is it was a complete corpse, and it doesn’t protect over the locked openings until there would be four [handbreadths].

רבי יוסי אומר השדרה והגולגולת - that in his Bet Din/court, it is like a complete corpse, and if he intended to remove them through a window, it does not protect the locked openings until there would be four [handbreadths]. And such is the Halakha.