
DUPLO bricks from LEGO are designed for younger children, aged 18 months to 5 years. In every dimension, they are 2x larger than traditional LEGO bricks. This is to make them easier for younger children to handle, and to make them less likely to be swallowed. DUPLO bricks were first introduced in 1969 in four colors. The line expanded to include licensed sets from Bob the Builder and Thomas the Tank Engine. DUPLO mainstays include farm, airport, zoo, and train themes.