Each UMIK-1 comes with a unique calibration file. You can download it from the UMIK-1 / 2 product page by entering the SN# of your microphone in the text box and click "SUBMIT".
Here are the relevant links:
https://www.minidsp.com/products/acoustic-measurement/umik-1
https://www.minidsp.com/products/acoustic-measurement/umik-2