waveshare8-Ch Ethernet Relay Module (B) with Digital Input, Modbus RTU/Modbus TCP Protocol, PoE Port Communication, with Various Isolation and Protection Circuits, Industrial Grade Rail-Mount Case

First off, I'm knocking off a star for the less-than-stellar documentation (such as the only MQTT example on the wiki page being for using their cloud-based solution) and needing to be configured utilizing the slightly sketchy VirCom software.Aside from that, though, this is a lovely little bit of hardware that's not really any more expensive than a Raspberry Pi or Arduino once you consider the extras you'd need to buy for the same functionality. Once you've connected it to an MQTT server, you can send it commands from anywhere on the network, and while you do need to send a command to poll the inputs, it's easy enough to automate that to have the inputs visible to anybody on the network who is interested as well.And since everything can be powered by a single POE cable, you can pretty easily set up a button panel to control your smart home stuff from anywhere you can get a POE cable without needing to worry about things like Wifi. I think you might even be able to power some LED's off the COM port in conjunction with the relays for some status lights (COM seems to output ~5v when running off POE), but I don't know how much amperage it outputs so that's very much a try at your own risk kind of deal.It's kind of a pain figuring out how to set it up and use it, but once you're past that, having network attached inputs/relays is pretty handy if you have a use for that sort of thing.