DescriptionThis hand crank generator adopts ABS outer shell, which has high strength, corrosion resistant,durable and can last for a long time. Fine workmanship and comfortable grip, easy to use. Perfect as an inspirational learning resource for young children.Features-Color: Green-Material:Plastic, magnet, metal -Size:8.00X5.00X5.00cm/ 3.14X1.97X1.97in-Voltage: 3V, maximum to reach 6V -The outer casing is made of transparent plastic, which can intuitively understand the principle structure of gear transmission. -This hand crank generator can improve hands-on skills, fine motor skills and problem-solving skills.-It can be used as a physics teaching experiment, great to cultivate students and kids hands-on ability. -It can be easily rotated to easily drive small motors, LED light sets, model light set, etc.-Nice birthday, Christmas or holiday gifts for your son. It's not only scientific experimental tools but also educational toys.