Neck King® and The Back King™
Check with your doctor if you have any injuries or medical conditions before using.
Stop using if you feel any numbness. This could happen if you stay on the bumps in one spot for too long; do not sleep on these products.
Do not work the area just below the back of the skull aggressively. This area can irritate cranial nerves more easily in some people causing numbness or a delayed numbness. Start with minimal use in this area to make sure this isn't a problem for you.