permeability of vacuum, \(\mu_{0}\)

https://doi.org/10.1351/goldbook.P04504
Fundamental physical constant by definition equal to 4π x 10E-7 H m-1, exactly.
Source:
Green Book, 2nd ed., p. 15 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)