Niederspannung
According to DIN EN 61140:2016 chapter 4.2 Table 1 (German version of EU standard EN 61140), Extra Low Voltage (≤ 50 V a.c. or ≤ 120 V d.c.) is defined as a sub-category of Low voltage (≤ 1000 V a.c. or ≤ 1500 V d.c.).