The NEW Duo X Joey Seat is an ideal option for stress-free outings when you have three children to accommodate. The Toddler Seat will transform your Valco Baby Duo X stroller into a triple stroller with a simple click into the front bumper bar housing. The All Terrain Duo X with Joey Seat is built to transport kids of all ages through snow, sand, grass and any kind of bumpy sidewalk. The Joey Seat can accommodate children from 6 months and up.