1st Generation FaceWare Pro: located on the inner left cheek.
Current FaceWare Pro: located under the right-side hook, next to the strap pass through slot.
EyeCare Pro: located on the inner left temple.
EyeCare Max Pro: Printed on the left temple, next to the strap pass through slot.
BodyWare Pro: located on the bottom right corner on the interior of the device.
LipWare Pro: Gently remove the detachable mouthpiece and the serial number will be etched into the device between the two mouthpiece connection points.