Concept phones are always interesting to check out, and this concept Nokia phone designed by British designer Matteo Trisolini has a rather interesting design. Dubbed the EC509 Green Core, it’s an eco-friendly cell phone that is wrapped in a carton with a free postage sticker which users can use to send their current mobile phone back to the manufacturer in. It’s powered by kinetic energy, so you can charge the phone by spinning it around your finger like you’d do a keychain. The phone comes with a recycled PET screen cover, LED battery indicators and other materials to reduce e-waste and protect the environment.