MATERIAL: The set uses high-quality, safe, and non-toxic plastic. The plastic edges are rounded and smooth without sharp edges or corners, enhancing safety and stability. This ensures parents' peace of mind and makes children happier. EASY INSTALLATION: After inserting two AA batteries into the train toy, turn on the switch to play (batteries not included). Domino Placement - Insert dominoes into the track from either end. CHILD SAFETY: These plastic domino products are made from non-toxic plastic that is safe and colorfast. The smooth edges ensure children's safety during play. Not recommended for children under 3 years old. CULTIVATE MULTIPLE CHILD SKILLS: Dominoes offer a recreational activity that encourages creativity and builds self-confidence. It's beneficial for developing participants' intelligence and creativity. More importantly, it can foster participants' willpower and teamwork. HOLIDAY GIFT: This is the perfect gift to stimulate children's thinking. Children can play together at parties and have many happy moments. Parents can also interact with their children. Suitable for children over 3 years old. Please disregard the '6 years and older' labeling on the product. Thank you for your support.