Arduino boards and modules are increasingly moving in the 3.3V direction, which can cause compatibility issues between 5V and 3.3V systems. This module contains 4 logic level converters, which rapidly converts the voltages bi-directionally. By putting this module between, for example, an I2C connection, a 3.3V module is again fully compatible with a 5V microcontroller and vice versa. The LV side must be supplied with the low voltage (3.3V) and the HV side must be supplied with the high voltage (5V).