With the electromagnet module you are able to control electromagnetic force with 5v dc supply. The electromagnetic forces are controlled by the high or low level in the signal force. You might even use the pulse width modulation (PWM) as an input to the signal pin and thus control the magnetic force in a systematic way by adjusting the width of the pulse. 

The working theory of electromagnet module is well known, the electric current flowing in a wire creates a magnetic field. To concentrate the magnetic field, 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. 

Features

• Working Voltage: 3.2 - 5.3VDC
• Working Current: 200mA(MAX)
• Load Weight: 1KG / 10N

Electromagnet module manual and arduino tutorial.