The curtain slide tape is only needed on the top portion of the curtain rod where the curtain rings come in contact with the rod. You can measure the circumference of the curtain rod by wrapping a string around the rod and then measuring the string length.
YES, you must use the included "ramp" and install the curtain slide tape so that it stretches across the extension point in the curtain rod and this will allow the curtain rings to slide smoothly across the joint in the curtain rod. Note - you must apply the Curtain Slide Tape after the telescoping or extension rod is installed because once applied, you will not be able to further adjust the length of the curtain rod without removing the curtain slide tape.
The Curtain Slide tape surface is a hard plastic teflon®-like material that is approximately 0.010 inches thick with a high-stick acrylic adhesive on one side. In comparison, Curtain Slide tape is about 5 times thicker than a normal piece of Scotch® Magic™ Tape which is 0.002 inches thick.
Since the surface material of curtain slide tape is very slippery, much harder and much more durable than other tape products, it is a terrific and long lasting solution for helping curtain rings slide easily across the curtain rod.
The Curtain Slide Tape will adhere to any curtain rod material including wood, plastic, metal and wrought iron. It is important to first properly clean the curtain rod to remove any dirt, soap, wax, etc.
Given normal use conditions where the curtain is opened and closed a few times each day, the curtain slide tape will last for several years before needing to be replaced.
YES, as long as you clean the top of the curtain rod very well, the curtain slide tape will adhere to a fluted curtain rod. It is recommended that you use the 3/4 inch width for any fluted curtain rod.