The Baby Jogger Car Seat Adaptor allows you to turn your stroller into a travel system by providing a place to securely attach your car seat to the stroller until your baby can sit in the upright seat. It is designed to fit several popular car seats including those made by Peg Perego, Maxi Cosi, Cybex, Chicco, Graco and Evenflo. *Car Seat Adaptor for double stroller holds one car seat and only one adaptor can be placed on the stroller.