1、This product is a relay expansion board specially designed for Raspberry Pi, with 8 relay controls and screw terminal blocks. Bring this product and use your for Raspberry Pi to control power equipment 2、Based on for Raspberry Pi 40pin GPIO interface, suitable for Raspberry Pi series motherboards/Jetson 3、Using high‑quality relays, allowing access to loads of ≤5A AC or ≤5A 30V DC 4、The product come with optocoupler isolation to avoid high‑voltage circuit interference 5、This relay module using standard guide rail designs, easy to install and use 6、Equipped with relay indicator light, easy to check the working status of the relay 7、Come with relay selection jumper cap, which is convenient to switch other pins for Raspberry Pi to control 8、Reserved control interface, convenient to use with PLC and other controllers Item Type: Relay Module for Raspberry Pi Trigger Signal: 3.3V/5V Number of Relays: 8 Channel Contact Type: One normally open and one normally closed Closing Current: 6mA (each channel) Through Hole Diameter: Approx. 3mm / 0.1inSize: Approx. 3.5mm / 0.1in 3.5mm / 0.1in 65mm / 2.6in 232mm / 9.1in 72mm / 2.8in 87mm / 3.4in 94mm / 3.7in 130mm / 5.1in 137mm / 5.4in R: Approx. 1.5mm / 0.1in 1 x Relay Expansion Board 6 x Long Rod Screw 2 x Short Rod Screw 2 x Nut 2 x Connection Column