For enterprises, placards are a main means to advertise for themselves. Nowadays, with advanced technology, more and more placards have appeared on the market, they are made from different material, such as: paper, wooden, copper, etc. Today, a new one – LED placard has gotten more and more in daily life due to its function. And you can also see the following link: www.toptrafficsafety.com .This placard can save maintenance cost with low power consumption.