  Ultra-SAXS can enhance the capabilities of existing SAXS/WAXS beamlines and
laboratory instruments. A compact Ultra-SAXS module has been developed, which
extends the measurable $q$-range with $0.0015 \leq q\mathrm{(nm^{-1})} \leq
0.2$, allowing structural dimensions between $30 \leq D$(nm)$ \leq 4000$ to be
probed in addition to the range covered by a high-end SAXS/WAXS instrument. By
shifting the module components in and out on their respective motor stages,
SAXS/WAXS measurements can be easily and rapidly interleaved with USAXS
measurements.
  In this paper, the design considerations, realization and synchrotron
findings are presented. Measurements of silica spheres, an alumina membrane,
and a porous carbon catalyst are provided as application examples.
