BI-Directional 8 Channel 3.3V-5V TTL Level Shifter

From the shop's description

8 CHANNEL BI-DIRECTIONAL TTL LEVEL SHIFTER This module uses an array of transistors with pullup resistors to provide an 8 channel bi-directional voltage level conversion (level shifting) for digital logic signals. Intended mainly for the conversion of signals between 3.3V and 5V logic levels this module provides a way of safely interfacing a 5V microcontroller to a 3.3V device or conversely 3.3V microcontroller to a 5V device without risking damage to both devices. Each of the 8 channels can also work in both directions meaning that bi-direction 2 way data signals can also be level shifted. Each side of the array can be supplied separately with the required level shifting voltage which can range anywhere between 1.8 and 6V.