?NSK? is a Shenzhen based Chinese manufacturing company with R&D and marketing departments. We have been focusing on VIDEO DOORPHONE SYSTEM and VIDEO ENTRY SYSTEMS for last 7 years, and following systems had been launched and marketed successfully:
CX system: Four wire, ?Start? Connection;
NCX system: Four wire, ?Distributor Bus? Connection?
NTW system: Two wire, ?Repeater Bus? Connection;
PBX system: PBX switch + Video distributor Bu connection;
DWL system: Digital wireless ,2.4G;
IP system: IP routing.