RPi Relay Boards Enable Pi to Control High-Voltage and High-Current Devices and Make Common Domestic Appliances Smarter. Supports for A + / B + / 2B / 3B. High quality relay, loads up to 250VAC / 5A, 30VDC / 5A. Onboard LEDs for indicating relay status. Photo link isolation, prevent interference from high voltage circuit. Relay control jumper, ensures to the relays by custom pins other than the standard pins. Comes with development means, including examples in wiringPi, WebioPi, shell, python, and bcm2835. Specification: Condiiton: New For GPIO interface: For connecting Relay screw terminal: For connecting target devices Relay indicator: LED on: relay NC is open, NO is closed LED off: relay NC is closed, NO is open Power indicator Relay control jumper: short the jumper: control the relay by standard I / Os used in the example code open the jumper: control the relay by custom I / Os via jumper wires Terminal Description: The expansion board has four terminals, each terminal has three pins for connecting external circuits Colour: blue Material: pcb Package Contents: 1 * Expansion Module for Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.