  The non-classical rotational inertia fraction of the identical cylindrical
solid $^4$He below 300 mK is studied at 496 and 1173 Hz by a double resonance
torsional oscillator. Below 35 mK, the fraction is the same at sufficiently low
rim velocities. Above 35 mK, the fraction is greater for the higher than the
lower mode. The dissipation peak of the lower mode occurs at a temperature
$\sim$ 4 mK lower than that of the higher mode. The drive dependence of the two
modes shows that the reduction of the fraction is characterized by critical
velocity, \textit{not} amplitude nor acceleration.
