MELISSA & DOUG: Self-Correcting Letter Puzzles. Learning about the alphabet is fun and challenging with these puzzles. The unique design of each individual puzzle prevents incorrect matches and guides children to correctly identify letters, their sounds, and their application in words. The games and activities included in this set provide for countless hours of constructive play while encouraging early reading skills and promoting other developmental skills. The entire set is housed in a 5-1/2x12-1/2x2-3/4 inch wood box. This package contains fifty-two wooden pieces. Recommended for ages 4 and up. Imported.