Supports for A+/B+/2B/3B/3B+/4B/5/Zero/Zero W/Zero 2W High quality relays, loads up to 5A 250V AC or 5A 30V DC Photo coupling isolation, prevent interference from high voltage circuit Standard rail mount bottom case Onboard for indicating relays status Relay control pin selection jumper, allows to control the relays by custom pins other than the default pins Reserved control Interface, allows to work with controllers like PLC Comes with development resources, including examples in wiringPi, bcm2835, python, python-bottle (webpage control), and crontab (cron job) Power supply voltage:5V Trigger signal:3.3V/5V Relay channels:8-ch Contact form:SPDT-NO,NC Closed current:6mA (per channel) Connector:screw terminal block Mounting hole size:3.0mm Due to different batches, the appearance, color and printed words of the product , which will not affect the use. Colour:Blue Material:PCB Size:232 x 72 (mm) Package Contents: 1 * Relay Extention Board Only the above package content, other products are not included. Note: Light reflection 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.