Allaboard for fun! Your budding little conductor is on track for chugga-chuggagood times with the Rollplay? 4-Piece Curved Track expansion pack. Four tracksections work exclusively with your Rollplay Steam Train 6V Battery Ride-On Vehicle (7221and 7721) to add curves to your indoor railway ― the more track sections youadd, the larger your track becomes! These curved track pieces snap together inseconds with the 24 ft. oval or 13 ft. circle that came with your RollplaySteam Train set. For maximum indoor thrills, combine curved tracks withFour-Packs of Straight Tracks (sold separately) to create different lengths andshapes for your train to run on. Wind around the room, down the hallway, aroundthe table ― the possibilities are endless. Get your imagination rolling!?