1. Wrist Lookee® Sleep Monitor:
The SN # is located on the back of the unit. You need to take it out from the wristband to find it. Please see the image below:
2. Lookee® Ring Sleep Monitor
The SN # is located on the side of the unit. Please see the image below. Or you can see the last 4 digits of SN# when you just turn on the device.
If you have any question, please feel free to contact us at Support@LookeeTech.com