Make sure to use cmdb_ci_handheld_computing if you want to be in alignment with the Service Graph connectors for Airwatch and Intune. That CMDB CI table also has fields for IMEI, phone number, carrier, etc..
Another option is Handheld Computing Device. That CI class includes fields for IMEI, MEID, ICCID, and Carrier. A field for Phone Number is not on the form by default but it is available on the table and can easily be added to the form.
Make sure to use cmdb_ci_handheld_computing if you want to be in alignment with the Service Graph connectors for Airwatch and Intune. That CMDB CI table also has fields for IMEI, phone number, carrier, etc..
