What will this battery-powered train do next? The adventure is up to you with the exciting 33873 Smart Tech Engine Set with Action Tunnels. Interactive play: The modern-looking Smart Tech Engine is the centrepiece of the play and can communicate with its surroundings, automatically responding with various train actions like lights, sounds and motion. By arranging the Smart Tech accessories in different ways around the railway track, you determine the trains journey and control the interactive play. Stop, go, play: When approaching the Smart Tech Bridge, the engine will automatically detect whether the stop signal is set to red or green. If the signal is set to red, the train will stop and wait to pick up the passenger who fits in the passenger wagon. Turn the signal back to green and the engine will start moving again automatically. Full of action: Each Action Tunnel creates a unique response from the Smart Tech Engine, and by actively moving them around the tracks, you change the trains journey. Use the red tunnel to stop the train, green to make it reverse in the opposite direction, and grey to make it honk its horn and flash its lights. Part of the BRIO World: The Smart Tech Engine Set is fully compatible with other BRIO World sets, tracks and trains, featuring classic BRIO magnetic couplings allowing for easy connection to each other and other vehicles. Full of interactive and imaginative fun, this BRIO World set activates children and helps them to explore the world around them in a fun and educational way. 33873 Smart Tech Set with Action Tunnels includes 17 pieces: 1x Smart Tech Engine, 1x Passenger Wagon, 1x Passenger Figure, 1x Smart Tech Bridge, 3x Smart Tech Action Tunnels, 9x Wooden Tracks, 1x Track Stop.