Type 40, formally known as a Type 40 time travel capsule, is an old model of transportation used by the Time Lords. While this ship may be an out-of-date museum piece for the Time Lords, it is still the pinnacle of advanced technology for most other races in the wide universe.
This ship is sentient. Fifteen-dimensional space fairing capsules can travel anywhere in Space-Time, including other universes. It's bigger on the inside and effectively infinite, being able to create space within itself, with various rooms serving different purposes, from libraries and pools to gardens. While not much is known about the ship's internals, it is from a society of advanced beings and can do virtually anything.
The main room is the control room from which you can drive the TARDIS, which houses a replica of the Eye of Harmony, the power source of the TARDIS.
Of course, this type 40’s chameleon arc is functional (the default setting is a police box), as well as being able to do anything that any other type 40 has been shown to do.
Despite the mention of the type 40 through the power, you can choose between any canon variant of the TARDIS that is shown in any media that is in the Doctor Who franchise.