Ok, so. Yes LeChange is official product by Dahua, somehow the kit you all talking about did disappeared from LeChange or Imou website or maybe it was newer there. Anyway if your sticker says nk168p083-nvr wich is (Lechange 16-Channel 4K UHD NVR with 3TB HDD and 8 4K Outdoor Night Vision Bullet Cameras) and you bought it for $600-$800 you saved a lot of money. But the problem there is no support for this product at all. So we all want to reflash it to Dahua. Your NVR is nvr4216-16p-4ks2 and your cameras is DH-IPC-HFW4830E-S. Each camera cost $200 & this Poe NVR about $350 plus hard drive $100 = $2,050. Finally to the point, I got the guy who is officially working for Dahua repair center in eastern European country. He was able to connect to my PC using Team Viewer and by connecting by USB serial cable RS232 hr reflashed my NVR to latest Dahua 4.0 firmware for $60. Now cameras little more complicated we will attempt to reflash them in couple days for $20 each since it have to be connected by UART and I just need special adapter not to solder cables.