The Baby Jogger Single and Double Car Seat Adaptor is one of the most important accessories you will ever purchase for your stroller. It allows you to use your car seat with your stroller until your baby is strong enough to be placed in a stroller seat. This car seat adapter works on the City Mini, City Elite, F.I.T. and the Summit. The universal is designed to fit several popular car seats including, Peg Perego Primo Viaggio, Britax Companion, Maxi Cosi, Teutonia and most Graco and Evenflo car seat models.  The Chicco adapter will fit the Keyfit30 or the Keyfit model.