What is in the set
Dyson sells the Purifier Cool under one family name in more than one filter configuration, and the machines look alike. Its own TP07 user guide documents three, on consecutive pages:
1. A machine supplied with a single combined HEPA+Carbon filter. 2. A machine supplied with SEPARATE HEPA and carbon filters — two pieces, bought and replaced independently. 3. The Purifier Cool Formaldehyde, which adds a PERMANENT catalytic filter alongside a HEPA+Carbon filter. Dyson's wording for the catalytic one is that you "won't need to change" it.
So before you buy anything for a Dyson Purifier Cool, the question is not which part number. It is whether your machine takes one filter or two.