This relay board module is a 5V 8-Channel Relay interface board. It can be controlled directly by a wide range of microcontrollers such as Arduino, AVR, PIC, ARM and so on. 8-Channel Relay interface Module board, each one needs 15-20mA Driver Current. Equipped with high-current relay: DC30V 10A AC250V 10A. Each relay has normally open and normally closed contact. The 8 channels are optically isolated, safe, reliable, anti-interference. Can be selected by jumper relay and TTL or ground. With power indicator, 8-way road has a status indicator. With a relay coil to absorb the diode protection. The circuit board size 140mm X 55mm. Mounting hole size 133mm X 40mm. It serves as an optocoupler isolation board. It serves as an optocoupler isolation board.