Keep connected and conserve power when your battery is low using ultra-power saving mode. (offer valid March 17-31, 2017). (Device will lock to carrier once a SIM card is inserted. For more datails on unlock options, call 1-800-SAMSUNG.). 5" SAMOLED screen. Android 6.0 (marshmallow). 5MP rear camera. 16GB capacity + microSD slot. 4G LTE.