Im using asus zenfone it is a very useful device it is a fast device ram is 3gb and 16 gb internal storage its a 4g smart phone I appricate that from asus but if we work more yime heatens faster it had a good hd display and the sound qualities are good enough and the services of asus is very good and we can contact to the tele service it was first 4g but now it volte through a recent update bvoz of asus zenfone I can use jio and charging quality is good and camera is also good I like this smart phone thanks asus