  We report the confirmation of a sub-Saturn-size exoplanet, TOI-1194 b with a
mass about $0.456_{-0.051}^{+0.055}$ $M_{J}$, and a very low mass companion
star with a mass of about $96.5\pm1.5$ $M_J$, TOI-1251 B. Exoplanet candidates
provided by the Transiting Exoplanet Survey Satellite (TESS) are suitable for
further follow-up observations by ground-based telescopes with small and medium
apertures. The analysis is performed based on data from several telescopes
worldwide, including telescopes in the Sino-German multiband photometric
campaign, which aimed at confirming TESS Objects of Interest (TOIs) using
ground-based small-aperture and medium-aperture telescopes, especially for
long-period targets. TOI-1194 b is confirmed based on the consistent periodic
transits depths from the multiband photometric data. We measure an orbital
period of $2.310644\pm0.000001$ d, and radius is $0.767_{-0.041}^{+0.045}$
$R_J$, and amplitude of RV curve is $69.4_{-7.3}^{+7.9}$ m/s. TOI-1251 B is
confirmed based on the multiband photometric and high-resolution spectroscopic
data, whose orbiting period is $5.963054_{-0.000001}^{+0.000002}$ d, the radius
is $0.947_{-0.033}^{+0.035}$ $R_J$, and amplitude of RV curve is
$9849_{-40}^{+42}$ m/s.
