I have bought lenovo vibe p1m from amazon in 2016 after 1 year works good and having grate battery backup.the battery is 4000mph which is inbuilt but really good than other phone it consists of android o.s. 5.0 that is lollipop having good user interface the battery.better sound quality microphone is also gaood.they are having great value for money style and look of phone quiet good but camera is also good which is 8mp.the ram of mobile is 2gb really it never hangs at all.processor works properly so no problem at all in mobile API.