Wawa:
There is a 35volt relay contact limit for that shield.
That's why I asked what OP is switching.8-channel relay boards can be configurated for opto isolation, with a separate 5volt relay supply.
That could make them safer for mains applications (if done right).
Leo..
Yeah I'm not sure I would trust or recommend the OP to use high voltage i.e. 110v-220v regardless if it stated it could, the shield I listed is of low quality but I'm working with nothing over 12v so it suits my use case and may suit his as well