The Lumia 640XL has a 5.7-inch IPS LCD display with HD resolution, 259 PPI pixel density It runs Windows Phone 8.1 with Lumia Denim OS The chipset is Snapdragon 400 with a quad-core 1.2 GHz Cortex-A7 processor It has a 1GB RAM and 8GB of storage space expandable to 256GB It has a 13MP rear camera with LED flash, while front camera is 5MP The phone is powered by a 3,000mAh non-removable Li-ion battery Connectivity options include dual microSIM support, 4G, Wi-Fi 802.11 b/g/n, Bluetooth 4.0, A-GPS, and has a microUSB 2.0 port