● SCIENCE MOTOR KIT: Comes with 6 x DC Motor, 6 x Battery Holder Case, 6 x Rocker Switch, 6 x Motor Mounting Bracket, 12 x Electronic Wires(3.92"), 1 x Heat Shrink Tubes(40cm⌀3mm), 66 x Plastic Gears, 6 x Shaft Propeller with 4 Vanes, 6 x Shaft Propeller with 3 Vanes, 5 x Bulbs, 3 x Bulb Holders, 3 x Buzzer Sounders, 5 x Crocodile Clip Leads, enough circuit accessories for kids DIY STEM science experiments ● COLORFUL SHAFT PROPELLERS: 12 Pieces 2 style different colors shaft propellers, 6 pieces 4 Vanes shaft propellers, 6 pieces 3 Vanes shaft propellers can meet your different needs, let you make science and STEM projects much more fun and more choices to fit your experiments ● DC MOTORS: Body Diameter: 28mm/ 1.06"; Mounting Hole Distance(center to center): 15mm/ 0.59"; Shaft Size: 10 x 2.0mm/ 0.39" x 0.08"(L x D); Motor Body Length: 38mm/ 1.46" ● WIDE APPLICATIONS: This complete electric motor kit good for kids experiment and explore basic electrical simple circuits. It can also be used in school in science, STEM, technology and design courses, easy to meet your project needs, properly educating some circuit knowledge would be a good interaction time with your kids together ● ATTENTION: Suitable for 6 + years, please read the circuit pictures carefully, use the correct circuit diagram to avoid short circuit, short circuit will produce high temperature and cause the battery holder case to melt and burned, the kids must use under the supervision of adults