What are these things called?

I am thinking about using them in my next DIY project. We can find them on top of the SMD LEDs of the main board. Are they some kind of diffuser? What are these called? Please tell me you know the name. Thank you.

LED Light pipe? I believe that’s the right term, we did an investigation into some custom PCB enclosure manufacturing a few years ago and that was what two of the manufacturers called them anyways.

Thank you. I Googled with your term ‘led light pipe’ and this is what I found:

A LED light pipe is an optical fiber or a solid transparent plastic rod for transmitting light from an LED mounted on a printed circuit board (PCB) to the user interface.

Thank you for pointing me in the right direction.

No problem happy to be able to help. As with so many other “electronics names” it makes sense once you hear it, but to guess at it without prior knowledge is like picking a needle from a haystack!