Calibrating ERIS data: as-built capabilities and performances of the instrument's inner calibration unit

ERIS (Enhanced Resolution Imager and Spectrograph) is the new AO instrument for the ESO Very Large Telescope. It includes the 1-5 micron camera NIX, the 1-2.5 micron spectrograph SPIFFIER (a refurbished version of SPIFFI), an Adaptive Optics module able to provide single-conjugate adaptive correction using both NGS and LGS stars and an internal Calibration Unit. The ERIS construction is under completion and commissioning at VLT UT4 will start on the 2nd half of 2020. The as-built capabilities and performances of the Calibration Unit are presented in this paper.