Actuator / Nozzle: The button you press. It has a final outlet hole that shapes the emerging foam, often into a fan or ribbon pattern.
Closure / Cap: The threaded part that screws onto the bottle to create an airtight seal.
Gaskets and Seals: Usually made of silicone, these ensure the system is airtight and leak-proof, which is crucial for creating the necessary pressure and suction.