Did you know that your child's car seat has an expiration date? Do you know how to responsibly retire an old seat once it expires? We're here to shed light on From a single to a double stroller! The Ypsi has 12 different configurations to accommodate your oldest and youngest child together in the same stroller by adding the Ypsi Double Adapters (sold Chicco KeyFit Car Seats: Compatible Strollers 1 oz Disposable Plastic Portion Cups with lid 2500 set X PACK