Precision frequency measurements began immediately, with a direct comparison to an Sr optical atomic clock with a relative uncertainty of 10 prepublished in late June 2024: 2 020 407 384 335 ± 2 kHz This implies an energy of 8.355 733 554 021 (8) eV and a wavelength of 148.382 182 8827 (15) nm. Improvements will surely follow.