SDA is a private owned company based on a wide range of door automation products, like Swing door openers, Slding door openers, Rolling door openers, Sectional Door openers, Road barriers and Access controllers. These products have the characters of multi-funtion, personal design, safe and long life. These products could widly used in the building of residential houses, factories, shops and offices etc. It will take you more convenience and efficient circumstance.