After looking around my old LEGO bricks I found a broken antenna that when held up to the light looked a lot like fiber optics.
This gave me the idea to use some LEGO antenna bricks as makeshift fiber optics for the sights on my WE G17 Gen 4. The result is really nice and works great in comparison to actual fiber optics.
I let the bulb at the end on for the reason that it will gather more light that way.
Don't have a printer yourself? Buy it from me in my Etsy shop here:
It is best to print the parts on their "backs" so you have a flat surface for it to adhere to the print bed.
Trim the end of the LEGO antenna which usually connects to the actual LEGO bricks.
Remove the supports from the printed parts and insert the LEGO antenna's from the front untill the bulb is snug against the sight.
Trim the excess from the back, but not to much because afterwards you will want to lightly sand/flame polish the antenna ends so they let more light through.
Mount to your WE G17 Gen 4 airsoft pistol and have fun.