An electromagnet is a type of magnet in which the magnetic field is produced by electric current. An electric current flowing in a wire creates a magnetic field around the wire, due to Ampere's law(see drawing below). To concentrate the magnetic field, in an electromagnet the wire is wound into a coil with many turns of wire lying side by side. The magnetic field of all the turns of wire passes through the center of the coil, creating a strong magnetic field there. Grove - Electromagnet can shuck 1KG weight and hold on. it easy to use, to learn electromagnet principle. Features Grove shape 1KG peak suction Low standby current Specification Working Voltage :DC 5V Working Current : 400mA Standby current : 200uA Load Weight: 1KG Documents: Please visit SeeedStudio Wiki page for more info about this product.