  We construct simple renormalizable extensions of the standard model where the
leading baryon number violating processes have $\Delta B = \pm \Delta L = -2$.
These models contain additional scalars. The simplest models contain a color
singlet and a colored sextet. For such baryon number violation to be observed
in experiments, the scalars cannot be much heavier than a few TeV. We find that
such models are strongly constrained by LHC physics, LEP physics, and flavor
physics.
