Led Display
where to buy LED display screen?

I want to buy an outdoor LED display screen for advertising,but I don't know where to buy and can buy very good ones?What are the most important when choosing a LED screen?

http://www.theledsigncompany.com/

http://www.outdoorsignsamerica.com/catalog.aspx?catid=outdoor_led

http://www.grandwell.com/

http://www.electronicsigns.com/full_color.htm

These are some of the best led sign companies