curtain end cap

I went to the local Bed Bath and Just Short and had a look at the curtain end caps and they were all $15+ so naturally I went home and designed and made my own. I have a couple calipers that are handy for measuring the proper diameter for the curtain rod. Curtin rods normally have 2 diameters on either end depending on the width of your window. My curtain rod was 0.65" on one end and 0.75" on the other. The provided 'thing' will need to be sized using a cylinder of the required diameter.