This is my new version of the bladetip for lightsabers with a thick walled polycarbonate tube, bought at amazon.com. This has 25mm O.D and 19mm I.D. The inside has been holowed out so the light will pass through better. I printed mine in transparent PLA with 100% infill . I took a piece of chomed plastic from the lid of a spraycan to make a mirror, see picture. It works great.