Chicco Corso Flex Modular SeatAccommodate two children in your Corso Flex Convertible Stroller by adding a second Full sized Modular Toddler Seat. The toddler seat mounts interchangeably into the upper position (either forward or parent facing) and the lower position (forward facing only) giving you maximum seating and storage flexibility. Build more configurations with your Corso Flex Stroller by adding a second Infant Car Seat Adapter Basket and a Chicco infant car seat. Usage