This is a safe designed constructed durable Educational STEM Toy. The kit features a low operating voltage for circuit components to ensure child safety during use. The science kit came with small circuits that allow kids to combine many projects. Kids will learn the circuit knowledge, parallel connection and series connection with flashing traffic lights, catapult aviation rockets, and radar activation, enabling hands-on exploration. Keeping them busy for hours. Includes a color manual with clear, easy-to-understand instructions for step-by-step circuit construction,an educational kit that promotes an interest in science. I purchased this as a gift and my grandson loves it.