  We consider the scattering of a quantum particle by two independent,
successive parity-invariant point interactions in one dimension. The parameter
space for the two point interactions is given by the direct product of two
tori, which is described by four parameters. By investigating the effects of
the two point interactions on the transmission probability of plane wave, we
obtain the conditions for the parameter space under which perfect resonant
transmission occur. The resonance conditions are found to be described by
symmetric and anti-symmetric relations between the parameters.
