Ensure the area of your neck where you are applying the sensor is completely clean and dry. The full surface of the adhesive is pressed against the skin of your neck. If you have a beard, please make sure to shave your neck, and if you have makeup, please remove it before applying the neck sensor. If the sensor continually falls off during the night, please email [email protected] quoting your reference number. Your reference number can be found on all emails received from us. We will send you extra sticky adhesives in this case.