When I was 9 I got a robotic arm from my grandfather and this is what I am reviewing. The box said it was for teenagers (14+) but when I made I was only 10. It uses a series of gears and motors to manoeuvre each main turning points on the arm and they all connect to a small cpu (central processing unit) by wires that run down the exterior of the arm and base. A significant percentage of the actual robot is the base, the reason being that it is where the 4 D-size batteries below the cpu. You control the gears and motors using the controller. Every thing is self-assembled and an easy-to-follow instructions booklet makes it very simple to build. Overall I think this is a great product and a good present for christmas or birthdays.