Updated cryogenic performance test results for the flight model JWST fine guidance sensor

The Integrated Science Instrument Module (ISIM) for the James Webb Space Telescope (JWST) has successfully completed its final cryogenic performance verification tests. The performance of the newly upgraded Fine Guidance Sensor (FGS) / Near Infrared Imager and Slitless Spectrometer (NIRISS) was evaluated in these tests. We describe some of the key guider performance results which have been obtained and compare them to previous results with an older generation of H2RG infrared detector arrays. The identification mode sensitivity improvement is described along with noise equivalent angle (NEA) sensitivity performance improvements in tracking and fine guiding modes. Tracking mode allows the Observatory line of sight to settle in advance of the fine guidance mode and also facilitates moving target observing. The NEA of the FGS-Guiders will in part determine the ultimate image quality of the JWST Observatory.