Ethernet cables are probably one of the least exciting tech accessories you own. But you may not realize they can do more than just connect devices to your router. They can also carry video, audio and power. However, just because they can do that doesn’t necessarily mean they’re the best option.

HDMI usually connects two devices that are relatively close together, but some people’s setups need video to travel over longer distances. This is one area where the same cables you use for Ethernet (category cables) could find a second use.

Ethernet cables won’t do that on their own. For this setup, you’ll need to buy HDMI extenders to pair with your Cat5e, Cat6 or similar cables. Those adapters put a transmitter at one end and a receiver at the other, while using the cable as the connection between them. That lets you send video much farther than you typically could with an HDMI cable.

Despite the familiar cable, this isn’t actually Ethernet networking. (AV over IP, on the other hand, does use your local network to transmit audio and video.) Here, the category cable is simply carrying the signal between two extenders. It could be handy if you already have an unused cable in your walls or you need to reach something distant, like a projector.

Still, it isn’t necessarily the best solution even for those cases. Active optical HDMI can also handle long distances, and some cables support formats like 4K at 120Hz that many extenders don’t. Think of category cables as a potentially useful option for some niche setups, rather than a go-to solution.

These same category cables can also carry multiple channels of analog audio. With the right adapters, a single cable can carry several channels. For example, a studio could use it to connect microphones in one room to recording gear in another without pulling a bunch of individual cables through a wall.

For most setups, standard XLR cables are easier and pretty cheap. But if the wiring is already there, category cable can be a clever way to replace several cable runs with one. Some setups also need shielded cable, especially if the microphones get power through the connection.

Speaking of power, Power over Ethernet (PoE) is where category cables can find a second life that’s more than just a clever gear hack. PoE lets one Ethernet cable carry both data and power. It’s especially handy for security cameras, Wi-Fi access points and other devices that aren’t near an outlet.

For example, a camera on your porch could use one Ethernet cable for both power and its network connection. Or you could run it to a Wi-Fi access point on your ceiling. The cable just needs to lead back to an accessory that provides PoE, like a compatible switch or injector.

Unlike the other uses, PoE isn’t just an oddball option, it’s a truly useful standard. However, you still need to make sure your equipment supports it and provides enough power for the device.