I use this phone(Lenova k4 note)last 11 month. Still working very nice.no any issues. Dolby attoms sound quality excellent. Speed wise super.camara quality also very god.worth for money.I stronly recommended this product.ram is working good.charging very speed. Battery backup also good.one day fully battery running.very comfortable handling. VR headset working is super.Easy to use.confirm this phone is best smart phone.