  We investigate universal relations in a spinless Fermi gas near a $p$-wave
Feshbach resonance. We show that the momentum distribution $n_{\vec{k}}$ has an
asymptote proportional to $k^{-2}$ with the proportionality constant--the
$p$-wave contact-- scaling with the number of closed-channel molecules. We
prove the adiabatic sweep theorem for a $p$-wave resonance which reveals the
physical meaning of the $p$-wave contact in thermodynamics. In contrast to the
unitary Fermi gas in which Tan's contact is universal, the $p$-wave contact
depends on the short-range details of the interaction.
