With the CYBEX Gazelle S2 Second Sibling Seat, you can convert the Gazelle S 2 Stroller (sold separately) from a single to a double that can carry both of your kiddos with the same level of comfort. The full-size Gazelle S seat can be used in parent-facing or forward-facing mode, and it can be attached to the stroller's upper or lower position. Its one-pull harness helps you quickly secure your little ones—a game-changer when you're strapping in two!