Google's attempt at providing mobile network services with the Project Fi is expanding, as it welcomes the first non-Google device to its lineup of compatible smartphones. The highly anticipated Motorola Moto X4 is joining the project when it launches at the end of the month.

The Project Fi Moto X4 will retail for $399. It will have a 16-megapixel front camera, and a 12-megapixel and 8-megapixel dual camera setup at the back. Users who will purchase the phone will have an option between a black and a silver unit.

The phone will have a 5.2-inch screen with a 1080p resolution and a battery pack with 3,000 mAh capacity. Under the hood, it is powered by a Snapdragon 630 processor.

Based on its specifications, the Moto X4 will be a midrange device, and will be the cheapest Project Fi phone once it is launched.

Currently, only Google's Nexus and Pixel phones are compatible with Project Fi. With the addition of the Moto X4, Google not only expands the project in terms of brands compatible with the service, but it also expands its target market by offering a more affordable handset that can use Project Fi.

On top of that, the search giant will make getting the new phone more enticing by offering promos for existing users who will trade in older Nexus devices. Subscribers will get a $165 value for trading in select Nexus devices. If users do this before Oct. 5, Google will give them a $50 bonus.

The Moto X4 is also getting the Android One treatment, which Google previously only applied to lower end phones. It seems that the company is also looking to expand the Android One program to more price points in the future.

With the Android One, Moto X4 will have a pure Android operating system, and will not include Moto features like Moto Voice and Moto Access, although it will keep Motorola's gestures and display customizations.