Progressive puzzles grow with kids. As preschoolers master the 3-piece puzzle, they then progress to the 4-piece, 5-piece, and 6-piece puzzles. Four puzzles included in each set. Easy slide box allows for quick clean-up. Large chunky puzzle pieces measure about 2x3" each. Made with 80% recycled content and printed with vegetable based inks. Conforms with CPSIA and ASTM standards.