  Recent experiments make it appear more likely that the order parameter of the
unconventional superconductor Sr$_2$RuO$_4$ has a spin-triplet $f$-wave
symmetry. We study ultrasonic absorption and thermal conductivity of
superconducting Sr$_2$RuO$_4$ and fit to the recent data for various $f$-wave
candidates. It is shown that only $f_{x^2-y^2}$-wave symmetry can account
qualitatively for the transport data.
