Features: Standard 40PIN GPIO extension header, supports series boards, Nano 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 LEDs 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 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 Dimension: 23.2 x 7.2 cm Color: As Shown Material: plastic Package Contents: 1 x Expansion 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.