It is going to be a tough sell for five-year-olds. SmartLab smart circuits kits require a basic knowledge of how electronic circuits work. It will be difficult for a five-year-old kid to even understand the instruction booklet despite the fact that it uses a lot of easy to understand illustrations. It will be possible for them if parents can assist them, but then it becomes less fun. Still, you can try if your child shows some natural interest in science subjects. But something like a Whacky Wheel kit would be more appropriate for them at this stage.