You wont get a volume knob in chinese units
All chinese units are different, its like the windows AC people used to get from Peshawar the smuggled ones chal gya tou chal gya warna nai chala. Shopkeepers will give you 2-3 version with things like this is normal lcd this is IPS lcd this is gorilla glass always the best one.
For the specs use apps like CPU-Z to confirm RAM
Sound quality of chinese units is not that great.
All chinese units have support for Front and Rear camera and steering wheel control.