A C7-style LED Light cover designed to fit over LED Pixels with a 12mm cover, such as the vast majority of Pixels used in Christmas displays. The flat side allows the LED to be placed along a rope or conduit arch etc, and sit flat rather than stick out and look odd.
I print these at 0.2mm, 3600mm/sec, 2 outlines, 3 top layers (it has a reasonably solid top) and it sticks OK to buildtak, but a skirt of 2 outlines with a distance of 0mm can also help stick them to the bed if you have issues.
The images show the cover installed on a pixel, and also a bare pixel so you can see the difference that the cover makes.
Infill does not matter, but to get the best top 100% infill and let it infill for 0.5mm or larger as this will make the tip a bit more solid. Even with 0% infill it will work fine.