This Microsoft Lumia 640 smartphone is a great choice for anyone looking for a high-quality device. With a 5-inch screen size and black manufacturer color, this phone is perfect for those who want a sleek and modern device. The phone is network locked to AT&T and operates on 4G and LTE connectivity, making it a fast and reliable choice for anyone who needs a reliable phone. The phone comes with 8 GB of storage capacity and supports MicroSD memory cards, which means you can expand your storage capacity if you need to. The device is designed with a single SIM card slot and runs on Windows Phone 8.1 operating system. This Microsoft Lumia 640 smartphone is a great choice for anyone who wants a high-quality device that is both reliable and stylish.