  We investigate three-dimensional left-handed and related meta-materials based
on a fully symmetric multi-gap single-ring SRR design and crossing continuous
wires. We demonstrate isotropic transmission properties of a SRR-only
meta-material and the corresponding left-handed material which possesses a
negative effective index of refraction due to simultaneously negative effective
permeability and permittivity. Minor deviations from complete isotropy are due
to the finite thickness of the meta-material.
