The DIY Hand Crank Butterfly Toy Set allows children to learn knowledge while having fun. The two gears are connected to the connecting rod and the crankshaft of the wings. When the gears rotate, the connecting rod will make a repetitive reciprocating motion, driving the wings to flap up and down. This scientific and technological toy enables children to learn about mechanical principles and scientific knowledge. This scientific toy not only cultivates children's learning ability, hands-on ability, and ability, but also increases their interest in exploring the endless . Features -Color:White -Material:Wood -Size:18.00X16.00X12.00cm/7.07X6.29X4.72in - Stimulates children's scientific curiosity with the diy hand cranked butterfly. Captivating children's interest in DIY toys. - Strengthens the bond between children and parents through butterfly diy making. Provides fun and educational tool. - Stimulate your child's interest in learning and lay the foundation for learning. Suitable for hands easily assemble. - Simple in structure, the wooden diy hand cranked butterfly toy is easy and convenient for you to use and operate, easily use. - This DIY toy is made of wood materials, durable and safe for longtime use. You can use with more convenience. Package list: 1 x set of DIY science butterfly material