Representative histograms of stellar properties for the Robo-AO SB sample (open) and the subset with identified candidate tertiary companions (filled). We note that the mass histograms refer to binary mass, except for our Troup et al. (2016) sources, which only have known mass values for the primary. The bias against detection of very low mass companions (lower right panel) is a reflection of the sensitivity limit of our data for faint sources (lower left panel).