When calling Signal-Tech customer service about a specific sign, you will need to provide the sign's serial number.
Facing the front of the sign, look on the right-hand lower edge of the frame. There will be a white label with the Signal-Tech logo and contact information.
The serial number is the 12 digit alphanumeric code afer SN: just below a barcode.
On older signs, the serial number is the alphanumeric number on the very bottom of the label and may have less than 12 digits.