Reflection extended X-ray absorption fine-structure spectroscopy (ReflEXAFS) is a unique tool in the investigation of real surfaces or systems with low surface coverage (monolayers or below). Exploiting the total external reflection phenomenon permits the probe beam to be confined to a few nanometres below the surface. Particular experimental apparatuses are needed for this data-collection mode and a description of some noticeable instruments and data-collection modes is provided in this chapter.