This is a 5V 4-channel Relay module with opto coupler is perfect for controlling up to 4 devices with a larger current. The optocouplers are used to Transfer the signals between two galvanically - isolated circuits, for example, circles. Your Arduino and your connected device with a larger current. Operating voltage: 5V Switching voltage: 10A 250VAC Dimensions: LWH: approx. 76mm x 56mm x 19mm https://elecena.pl/product/17485424/4-relay-module 2021-03-29 https://elecena.pl/product/17485424/4-relay-module 2024-04-29