Discover a beautiful underwater world. Features a colorful ocean scene with 18 hidden dolphins that can only be seen when the lights go out. Puzzles help develop fine-motor skills, hand-eye coordination, memory, focus and concentration skills. Plus, they offer a great way to spend time with family or friends, building relationships and making memories. Quality, thick pieces ensure a tight interlocking fit. 500 pieces. Measures 21x15" when complete.