trackmaster motorized engines from fisher-price have been redesigned so you can experience the island of sodor like never before! with enhanced speed and performance, these engines go faster and climb steeper inclines, driving thomas & friends to greater speeds, taller heights and bigger adventures! flip the switch and watch gordon race along on another exciting journey. the no. 4 blue engine is the perfect addition to your collectable, expandable, motorized trackmaster world! ages 3+. requires 2 aaa batteries.