This 16 bits instrument represents a large step forward in the field of electrical resistivity measurement (VES). It is the ideal instrument for subsoil groundwater prospecting from shallow to medium depth, studies of salt water contamination in fresh water layers, archeological prospecting. Reliable and portable, the 16GL system is characterized by really first-rate performances at a really affordable price. The possibility to download data through the RS-232 port enables a quick interpretation with the SEV2000 interpretation software. It is recommended, as to exploit its capabilities, to use it in conjunction with one or more P-100 rechargeable accumulators.