Lucky Doug solar robot kit includes 190PCS, not only assemble 12 different robots, but also can move on land or water (powered by solar energy, without battery), allowing kids to experience the environmentally friendly technology of converting solar energy into electricity. Recommended by education experts, suitable for children over 8 years old The solar robot kit comes with 190PCS easy-to-build parts and accessories and detailed instructions, allowing children to use their unlimited imagination to build and create their own robots.Suitable for Christmas gifts for boys and girls over 8 years old, and is committed to supporting their creativity as children grow up. This is an ideal toy to encourage young children to learn mechanics and engineering. STEM Educational Toys Product Troubleshooting Step1:Test whether there is a problem with the motor Please connect the wires of the motor to the positive and negative poles of a battery. If there will be a sound, it means that the motor has no problem, and it may be an assembly problem. Step2:Test whether there is a problem with the solar panel Please connect the wires of the motor to the positive and negative poles of the solar panel. If there is no response, it means there is a problem with the solar panel.