BARCELONA—The Fairphone 2 isn’t new to Mobile World Congress; it’s already available for sale in Europe and is being shipped out to consumers who pre-ordered. What makes it special is that it is completely modular, similar to Project Ara, which is expected to have a 2016 test launch in Puerto Rico.

Fairphone 2 functions on the same principles as Project Ara, where every component from the screen to the battery to the processor is completely user-replaceable, but the two projects have their differences.

“The idea [behind] the design of these modules is to make it easy to maintain and keep it alive for as long possible,” Fairphone’s Chief Technology Officer, Olivier Herbert, told me here at MWC.

“We use this modular design to extend the lifecycle of the phone, that’s different from using the modular design for customization,” he said. “That has never been a goal of the company.”

Instead, the focus is on environmental and social concerns; the devices are “easy to repair and easy to maintain,” and cut down on waste.

The Fairphone 2 is basically a Nexus 5 in terms of hardware. There’s a 5-inch 1,920-by-1,080 display, a Snapdragon 801 processor clocked at 2.26GHz, 2GB of RAM, 32GB of internal storage, 8-megapixel rear-facing camera and 2-megapixel selfie camera with a removable 2,420mAh battery, dual-band Wi-Fi, and 4G LTE capabilities.

In the future, Fairphone does envision giving users the option of upgrading modules, which would allow the Fairphone 2 to have components that can boost RAM, refresh the camera, and add functionality like NFC, but at the moment, there are only replacement parts, sold through its website.

“So far our market size is limited to the number of devices we have,” Herbert said. “We cannot afford to build a whole family of modules.”

In the meantime, the company will make the documentation available for third-party component support, which may provide users with different upgrade options, though this isn’t the primary goal of the company.

The Fairphone 2 torn down (see image), shows how fundamentally simple the device is. It’s no surprise that it has a 10 out of 10 rating on iFixit, compared with the AppleiPhone 6s’s seven and the paltry two for the Google Nexus 6P$499.00 at Google Store. The LG G5 is partially modular in some ways; you can click open the bottom and slide out the battery, but it’s nowhere near as modular as the Fairphone 2, which can be disassembled with only a single tool—a Phillips 0 screwdriver.

Taking apart the Fairphone 2 is easy. You start by peeling off the back, which gives you access to the battery, dual-SIM card slots, and microSD card slots. After you remove the battery, there are a set of blue locking clips at the bottom. Once unlocked, you can slide out the internal frame, giving you access to all the internal components, including the processor, speaker, and camera module. The Fairphone 2 uses two types of screws—the Phillips ones come with blue circles and are user serviceable, while the torx screws are not. The display pops out easily, and the rest of the components can be unscrewed. Putting the phone back together is simply these steps in reverse. Herbert was able to do it in three minutes.

Currently, the Fairphone 2 is officially sold with Android 5.1 Lollipop, but it is very developer-friendly. I saw Fairphone 2s running Android, Sailfish, Ubuntu, Android without Google services, and Firefox OS, all courtesy of the developer community. There is strong support for the developer community and Herbert said they, “do provide the development environment, the stack, the source code, the binaries to recreate the AOSP+, without any Google services.”

The Fairphone 2 is currently only sold in Europe. As for a U.S. launch, you’ll probably have to wait for the Fairphone 3. “We looked into it, [but] the cost of doing a North American version is too high,” Herbert said. “We’re not going to do it with this one, but the next one.”