By building two or three blinds on one headrail, operation of the blinds are easier. Furthermore, you now create less stress on the hardware and components of the window treatments. You will still receive one valance covering all blinds to give you that finished look. When entering measurements you must enter the total width and then select two on one or three on one headrail. Please note, the blinds will have a 1/2 inch space in between them to accommodate the single headrail construction. If you have any questions, please consult one of our customer service representatives for more information