This phone lenovo a6010 I am typing this with this phone and iam won’t notice any types of lag one thing thats is not good on this device 2 mp front camera overall rear camera is good but 8k there are the better options like rwdme 4 or even k6 power but battery is lasting me 1day and when its comes to the build quality this is avrage in myopinion android is 5.0.2 lollipop when you installed app third party like vidmate or some other stuff you can use only 1/2 hours and its says you is that app is not responding so buy this phone second hand thats good in my opinion ok good no lag good camera