Ecobee makes some of the best smart thermostats on the market, but like its rival Nest, the company may not be satisfied with that tiny sliver of the smart home gadget action. Dave Zatz of ZatzNotFunny previously revealed that the company was quietly working on a smart home camera, and now he’s discovered images of a contact sensor as well — and that suggests we’re only looking at the tip of the iceberg right now.

You see, a contact sensor is a fundamental piece of a larger smart home ecosystem, one where opening and closing doors and windows can trigger other things, like alarms, lights, or adjusting the temperature. (When the two halves of the sensor move away from each other — say, one of them on a swinging door — the system knows when it’s open or closed.)

But Ecobee doesn’t (yet) sell a lot of other smart home devices, and a contact sensor needs to communicate with some sort of hub to actually tell your home whether your door or window is ajar.

Theoretically, the sensor could be a standalone device that talks to, say, Apple’s HomeKit, designed to stand on its own merits and be part of a mix-and-match smart home system — but I’ve got a different hunch. You see, both Amazon’s Ring and Google Nest have shown what you can do by combining cheap contact sensors and a hub: you can create a pseudo DIY, modular home security system like Nest Secure or the inexpensive Ring Alarm. (Never mind that Amazon still hasn’t combined its sensors and cameras in any intelligent way quite yet. I have some at home.)

That strategy can’t have gone unnoticed by Ecobee, which surely saw Google snap up its rival Nest and just the other day turn it into its sole smart home brand, and witnessed how Amazon has been quickly acquiring a piecemeal empire of smart home brands including Blink, Ring and Eero.

When I contacted Ecobee, a representative played off the image as a “render”: “We’re always innovating and developing new ideas when it comes to hardware iterations and concepts — if it’s in the smart home world, you can bet we’re exploring it. This was one idea that was interesting enough to render.”

But if it’s real and part of an alarm system, we can probably expect even more smart home gadgets from Ecobee. There’s an awful lot of components — motion sensors, window break sensors, smoke alarms, etc. — that can theoretically build such a system out.