Baby Jogger Car Seat Adaptor - The car seat adaptor is one of the most important accessories you will ever purchase for your stroller. It is designed to fit several popular car seats including, Peg Perego Primo Viaggio, Britax Companion, and most Graco and Evenflo models. Compatible with any City Series, Performance Series or Q-Series single strollers and works with car seats that hold infants up to 20 lbs. and less than 26" tall. Car seats adaptors are model specific. Mfr Part Number: J7180