Features: brand new and high quality This board is helpful for connecting digital systems (like a 5V microcontroller) to a high-voltage or noisy system. This board electrically isolates a controller from the high-power system by use of an opto-isolator IC. This IC has four LEDs and four photodiodes built-in. This allows the low-voltage side to control a high voltage side. We often use this board to allow a microcontroller control servos or other motors that use a higher voltage than the TTL logic on the (3.3V or 5V) micro,and may cause electromagnetic interferance with our system as the motors turn on and off. This board will isolate the systems, creating a type of electrical noise barrier between devices. Specifications: Material:PCB Net Weight:96g Note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Optocoupler Board