Metali the Robot is part of the Build Your Own Robot series from The Young Scientists Club. It comes with a module (circuit board), a shell, a frame, and wheel and axle.
Metali moves using a worm gear, which is driven by the motor and fits into another gear that looks like a jagged circle. You connect the wires from various sources under coils. It was extremely fun to play with, and it stops and beeps whenever it detects metal. The sound is a loud beep.
Fun as it may be, there were some problems. It was hard to connect the module to the frame and get the screw in. It also had some problems with moving. The wheel and axle movement was very hard to maintain. You need a very small screwdriver (not included) and AA batteries.
Sometimes it was easy to complete and assemble; and other times it was difficult. It has a simple structure but some technical kinks to smooth out.
There are also other robots in this series: Infra, which is controlled by infrared light; Hurdle, which detects obstacles; and Sunny, which is controlled by light.
Overall, I rate Metali the Robot 4 smiles out of 5.