Features and SpecificationsTo start with the specifications, the Karbonn A21 has a 4.5-inch TFT display with a 480x800 pixel resolution. It is powered by a 1.2GHz dual-core CPU, but has an underwhelming 512MB of RAM. It runs on Android 4.0 ICS straight out of the box and there is no information whether it can be upgraded to 4.1 Jelly Bean. The best part is that the OS is a vanilla experience with a minimalistic skin that only Android veterans will be able to identify. To the everyday user, it is a near vanilla Android experience and that is a very good thing. The Karbonn A21 has 4GB built-in storage that can be expanded up to 32GB via a microSD card.