For use with the mounted solar cell and motor. A 12V 24W S.B.C. bulb in a metal socket mounted on a folded metal base 100 x 63mm with a pair of 4mm sockets. The power rating of the bulb has been chosen so that when it is placed in front of the solar cell sufficient power is produced to run the motor effectively whilst avoiding the risk of damage to the cell by excess light and/or heat.