1, Small and sturdy design, with the module you can easily extend Raspberry-Pi projects to IoT/industrial control applications. Support for Raspberry Pi A+ 3A+ B+ 2B 3B 3B+ 4B ( NOTE: the item not include Raspberry Pi). 
2, 8 channels SPST-NO power relays (Single Pole Single Throw, Normally Open). Contact rating (each channel): 5Amp/250AC or 3Amp/30VDC.
3, Power on LED indication, relay action LED indication corresponds to each channel.
4, Dual PCB design, ensure the electrical insulation between the relay module switch and the Raspberry Pi, to avoid damage to the Raspberry Pi due to the high voltage of the switch.
5, 2x20pin expansion header connector on board, all GPIOs of Raspberry Pi can be connected. But cannot support multiple HAT stacking.

Datasheet: https://www.czh-labs.com/tmp/madeimg/datasheet/d-1336.pdf