This alphabet wooden puzzle help kids learn the ABCs as they match letters to pictures. The self-correcting feature refers to the pieces having only a single match each, which ensures that kids correctly fit them together to develop a sense of mastery. This set includes capital and lowercase letters. You can separate several interlocked puzzles into two pieces. There are several ways to enjoy the Melissa & Doug letter puzzle. Parents can ask their children to match an alphabet piece to the correct picture and identify the letter by name. Children can also speak the letters sound and trace over the lower- and uppercase letters with their fingers, and they can increase the number of puzzles as they continue to develop their skills. This Self-Correcting Alphabet Letter Puzzle is an exceptional gift for kids ages 4 to 6 years.