I have a sit and stand stroller from Babies R US ( the only place I know to get them) The front seat can hold a car seat, or you remove the bar that holds the car seat for a regular seat with a little snack tray. The back seat is a little bench seat with a place for them to stand and handles they can hold onto. There is also a seat belt to hold them in, and a strap you can put behind them if they are stand so they won't fall backwards. It is so great for things like the zoo - instead of your older child buckling in and out of the seat, they can stand and watch the scenes go by, then hop out for a closer look, and back in when they're ready to continue on. There is also still a basket underneath to stash stuff. I have had as many as 4 kids on here at once when I was desperate! One in the infant seat, 2 skinny booties on the bench seat, and one standing. I LOVE this stroller!