The type plate on the rear panel shows type number and serial number. See illustrations on page 2-5 and 2-6. Installed options are listed under the menu User Options - About, where you can also find information on firmware version and calibration date. See page 2-15. The CNT-91R/AF version is identified by a unique identification marking, or UID. This permanent tag contains a barcode and allows customers to track easily their inventory and property.