  We present physical properties of two submillimeter selected gravitationally
lensed sources, identified in the Herschel Astrophysical Terahertz Large Area
Survey. These submillimeter galaxies (SMGs) have flux densities > 100 mJy at
500 um, but are not visible in existing optical imaging. We fit light profiles
to each component of the lensing systems in Spitzer IRAC 3.6 and 4.5 um data
and successfully disentangle the foreground lens from the background source in
each case, providing important constraints on the spectral energy distributions
(SEDs) of the background SMG at rest-frame optical-near-infrared wavelengths.
The SED fits show that these two SMGs have high dust obscuration with Av ~4 to
5 and star formation rates of ~100 M_sun/yr. They have low gas fractions and
low dynamical masses compared to 850 um selected galaxies.
