How Parking Guidance System Works: Firstly, UD takes use of ultrasonic wave to detect the car space to see if it is occupied by vehicles and transfer relative command to LED Indicator which will turn from green to RED when occupied, or it will keep GREEN; meanwhile, the UD transmit its status message to ZCU immediately, and ZCU will collect and forward the information to CCU; CCU processes these data and sends the relevant command to ZCU and LED panel. We have the most successful cases in China, pls kindly note below about some of them: c1 April, 2007 700 cars Singapore causeway point(OEM) 2 April, 2007 300 cars Singapore NorthPoint shopping plaza(OEM) 3 May, 2007 1400 cars Singapore Jurong Point Shopping Centre(OEM) 4 July, 2007 2000 cars Xiamen Hexiangxi Road 5 August, 2007 590 cars Singapore Paragon Shopping Center(OEM) 6 Sep, 2007 1800 cars Shenzhen Headquarter of Wal-mart 7 Sep, 2007 600 cars Singapore Square 2(OEM) 8 Dec, 2007 400 cars Kunshan Parking lots of civil gymnasium 9 Dec, 2007 500 cars Singapore Millenia walk shop(OEM) 10 Jan, 2008 300 cars Beijing Parkson Shopping Center 11 March, 2008 2100 cars Taipei Taipei municipal CarPark 12 April, 2008 1200 cars Singapore City Square Mall(OEM) 13 April, 2008 310 cars Indonesia Cambridge city square of Medan 14 April, 2008 300 cars Wuxi YAOHAN(800buy) Department Store 15 May, 2008 200 cars Changchun CHARTER Shopping Center 16 May, 2008 700 cars Tianjing Railway Station 17 May, 2008 200 cars Weifang *****