NLTT 11748 is the first detached double white dwarf (WD) binary system where eclipses have been discovered. It is also the first such system including a low mass, helium core WD. I will present the discovery of the system, and the interesting astrophysical phenomena that can be observed in it. One of those is the relativistic beaming effect, where the unique WD mass-luminosity relation leads to a relatively large beaming-induced variability amplitude, which we were able to detect from the ground. Finally, I will briefly discuss our plans to look for additional similar systems.
