CEFALY uses gentle electrical pulses to calm the nerves that transmit migraine pain. The ACUTE mode relieves symptoms during an attack. The PREVENT mode makes your trigeminal nerve less sensitive, so you have fewer attacks. Place the electrode on your forehead, attach the device, choose a mode, and feel the soothing stimulation. Adjust the intensity to the level that you prefer. Comes with one electrode, black case and operating manual.