The South Pole Telescope (SPT) with it’s 2500 sq. degree survey discovered 81 strongly lensed high-redshift dusty star-forming galaxies (DSFGs). These sources were selected at 1.4 mm and have multi-wavelength imaging. ALMA has already measured the spectroscopic redshifts for nearly all of these sources. ALMA high resolution 870 micron images have also allowed the creation of reliable lens models for nearly half of the sample. These lens models provide a wealth of information about the background source and the foreground lenses. We can determine the magnifications and intrinsic properties for the background sources. Whereas mass function, mass profiles and mass to light ratios can be obtained for the foreground lenses. Both the lens and the background sources are selected in a relatively unbiased manner based only on mm-flux from the background source. Thus, we will be able to study dark matter fraction in galaxies across cosmic time for the foreground lenses and the stellar mass content in both the foreground and background galaxies independent of redshift or mass selection bias.
