4 Channel Relay Hat Board For Raspberry Pi 4B/ 3B+ (Plus)/ 3B/ 2B

GeeekStudio 4 Channel Relay Hat Board [Description] 4 Channel Relay Hat Board For Raspberry Pi is one of the "docker pi" module. It has 4 channel relay that you can put it on your smart home project. This four-channel relay uses high-quality relay modules combined with the most popular microcontroller technology to communicate with the Raspberry Pi. You can use multiple modules stacked together for use. You can stack up to four layers. Switch the I2C address of the device through the DIP switch on the circuit board to ensure that the four-layer module gets different addresses, thus avoiding the problem of address duplication. The module is very fast, easy to install, and supports multi-language development, making it ideal for smart home projects. Note: The 4pin pin is a backup that supplies power to future products. You can ignore those pins. Please do not connect any device to that pins. [Features] Easy to use 4 channel relay Support I2C protocol Support for stacking Support address switching by dial switch Support multi-language programming Support 3A 250V AC Support 3A 30V DC Support relay status light prompt [Package Includes] 1x 4 Channel Relay Hat Board 4x M2.5x11+6 copper stick 8x M2.5x5 screws & nuts 1x Instructions Note: Raspberry Pi is not included. [Technical Support]