It’s been almost a year since Facebook first unveiled its ambitious AR vision called project Aria. While it was mostly about conceptual ideas and providing a “sensor platform” to developers, we never got to hear more about it — until now.

A new product manual, first spotted by Protocol, describes what this prototype device might look like and what it’s meant to do. The hardware is codenamed Gemini EVT (engineering valuation test), and it doesn’t have an in-built display. So don’t expect Google Glass-like AR tricks from it.

The device has four cameras and three buttons for power, capture, and mute. It also has a series of LEDs to let passersby know that the device is active and recording. The mute switch also turns to privacy mode, which supposedly stops recording sound. The manual doesn’t have any details on the cameras’ specifications.

The Gemini EVT charges through a USB cable with a proprietary port on the other end.

The manual also notes that you can set up the device through an iOS app called Ariane. This will also tell you about the device’s charging status and the data it’s collected.

It’s important to keep in mind that this is a prototype device, and might not be ever available for purchase — even if Facebook is testing a bunch of these. But never say never: we know that the social networking giant is making smart glasses in partnership with Ray-Ban, sans AR. Those could eventually arrive in the market at some point. Keep an eye out.

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