Nest’s smart doorbell can only be installed on homes that have the right kind of doorbell wiring, so to open up the product to everyone else, Google has started to sell an adapter that lets you plug the doorbell into an outlet inside your home.

It’s not the most elegant solution in the world. You have to drill a hole through your doorframe in order to feed the wire from inside your home to the doorbell on the outside of it. But it’s at least some kind of solution, and it might make sense for offices located inside of larger buildings that want to watch their own front door.

Other companies just sell battery-powered doorbells

The adapter isn’t made by Google, but by the company Ninety7, which is mostly known for making a lot of silly looking battery adapters for smart speakers. It’s being sold through Google’s online store, though, where it’s available for $29. Plenty of other power adapters are available from other companies — you can find a bunch of cheaper options on Amazon — but this is the first time Google has sold one directly.

Other companies have solved the wiring problem by releasing battery-powered smart doorbells. Ring’s cheapest two smart doorbells are battery powered, lasting for a quoted six months to a year.

That said, it seems like making a battery-powered doorbell can come with some complications. August recently released a battery-powered doorbell that was pulled from the market just weeks after release due to poor connectivity issues. It’s not clear what went wrong, but a battery-powered smart device would necessarily have to limit its use of battery-draining features, like Wi-Fi, which could lead to problems.