Electrodes, TENS, Misc. - Cefaly Accessory, C2 Electrode (Pack of 3) : Cefaly is a wearable device, clinically proven to quickly treat acute migraine attacks and prevent future episodes. Most migraines involve the trigeminal nerve, the largest and most complex cranial nerve. The top branch of the trigeminal nerve can be accessed through the skin on the forehead. Cefaly sends tiny electrical impulses through the self-adhesive C2 Electrode that is placed on the forehead to stimulate the trigeminal nerve, reducing the frequency and intensity of migraine attacks. You can use the C2 Electrode up to 20 times before you must replace it with a new one. This is an add-on accessory to the Cefaly Migraine Treatment and Prevention Kit. It comes is a pack of 3 Cefaly C2 Electrodes.