What is a roller blind? 
A roller blind is a fabric, rolled over a tube, that unrolls vertically to cover a window. It could work with ball chain mechanism, a spring or with motor.



In some cases the tube is put in a head box for getting a more esthetic look and to hide the moving mechanism. Roller blinds “Zebra”, “Double” or “Day and night” consist or double fabric with horizontal stripes, alternating with transparent stripes. The light quantity could be easily controlled by evening of the horizontal stripes.