1)high quality roller blinds 2)low voice, easy to install 3)ISO, ... certificate 4)manual,wireless available Principle SHIDAI electric roller blinds system use 220V tubular motor (A built-in and ... can be choosed 50mm, 70mm, 80mm or 110mm, underbeam made by white paint luxurious heavy rail, top-grade quality. ... also can use computer platform, multimedia central control system. blackout roller blinds