Review on 4M Green Science Dynamo Torch - DIY Mechanical Green Alternative Energy Lab - STEM Toys Educational Gift For Kids & Teens, Girls & Boys by Joyce Swihart

I thought when I bought this that it would be harder to assemble but I was pleasantly surprised. My 8-year-old built it in an afternoon with very little help from me. The LED is sufficiently bright to be seen on the ceiling during the day, and the easy-to-follow instructions also come with explanations of different electricity facts (we both liked that!). The cranking action has audible sound and the device does not hold a charge (it's not supposed to hold a charge) so my son was not able to light his bedroom after bedtime as stealthily as he'd hoped (ha ha). Definitely a worthwhile purchase. :-)