Please note: Raspberry Pi is not includedOverviewThe RPi Relay Board (B) is an expansion board with 8-ch relays for Raspberry Pi. It gives your Pi the ability to control high voltage products such as home appliances.FeaturesSupports Raspberry Pi A /B /2B/3B/3B /4BHigh quality relays, loads up to 5A 250V AC or 5A 30V DCPhoto coupling isolation, prevent interference from high voltage circuitStandard rail mount bottom caseOnboard LEDs for indicating relays statusRelay control pin selection jumper, allows to control the relays by custom pins other than the default pinsReserved control Interface, allows to work with controllers like PLCComes with development resources, including examples in wiringPi, bcm2835, python, python-bottle (webpage control), and crontab (cron job)SpecificationsPower supply voltage: 5VTrigger signal: 3.3V/5VRelay channels: 8-chContact form: SPDT-NO,NCClosed current: 6mA (per channel)Connector: screw terminal blockDimension: 232 × 72 (mm)Mounting hole size: 3.0mmDimensionsWhat’s in the box?1 x RPi Relay Board (B) 1 x Rail mount bottom case 1 x Screws pack ResourcesWiki : www.waveshare.com/wiki/RPi_Relay_Board_(B)