The smartphone, sporting a 4.5-inch screen, 1.2 GHz quad-core processor, 1GB RAM, 5MP camera, 8GB memory expandable upto 128GB and 1,830 mAh battery, has been launched exclusively on Microsoft brand store at

"We are introducing Lumia 638 which is the most affordable 4G smartphone on Windows Phone 8.1. It aims to address the consumers demand for a device that lets them enjoy uninterrupted video content," Nokia India Sales a Microsoft Mobile Oy subsidiary, Marketing director Raghuvesh Sarup said.