The Comfort Fix Isofix base is compatible with the Hauck Comfort Fix car seat. Features: - The Isofix Base can then be used as a practical addition to the following Hauck pushchair sets: Atlantic Plus Trio Set, King Air Plus Trio Set, Maxan 3 Plus Trio Set, Maxan 4 Plus Trio Set, Rapid 3 Plus Trio Set, Rapid 4 Plus Trio Set and Soul Plus Trio Set