  A tabletop-sized Kibble balance (KIBB-g1) designed to directly realize mass
at the gram-level range with uncertainties on the order of parts in 10$^6$ has
been developed at the National Institute of Standards and Technology (NIST).
The masses of a nominally 5\,g and 1\,g weight were determined with 1-$\sigma$
standard uncertainties of 9.0\,$\upmu$g and 6.7\,$\upmu$g, respectively. The
corresponding relative uncertainties are $1.8\times 10^{-6}$ and $6.3\times
10^{-6}$. The construction of the instrument, capabilities, and full
uncertainty budgets are presented in this manuscript.
