Summary: We wanted a second base for my car, but since I stayed home longer from work there was no need to get it out of the box and use. BIG MISTAKE!!! We just went to use this last week for my 4 month old & it does not work with our Maxi Cosi carseat. I don't understand why this is the only base that is sold through Babies r us for this line. We have the Maxi Cosi 35, this base is not compatible.