LEGO® DUPLO® Railway Expansion Set for ToddlersRailway Tunnels and Rails Expansion Set (10425) is a toy that lets toddlers have even more exciting adventures with their train sets. Preschoolers aged 2 and up can add a tunnel and additional track segments to their LEGO DUPLO® Town interactive train sets (10427 and 10428) (sold separately)® and learn in a fun way. This creative building toy includes a tunnel model and a 10-part railway track including a funnel and switch so toddlers can change the direction of the train. When the interactive trains from sets 10427 and 10428 roll over the action tile, the dark tunnel is illuminated. This educational toy promotes the development of toddlers.When preschoolers expand the railway line with the toy tunnel, they develop spatial awareness.