Light-up button activates cheerful music and fun sounds Plays imaginative phrases and three sing-along songs Dig into learning and play with the Go! Go! Smart Wheels Bulldozer by VTech. This busy bulldozer is perfectly sized for little hands and entertains your child with a light-up button that activates phrases and sounds. The bulldozer also responds to SmartPoint locations on Go! Go! Smart Wheels playsets (sold separately) with fun responses, sounds effects, lights and music. Your little builder will hear about the letter "B" and the name of the vehicle through imaginative play. Let's clear the road!