A two-part Keycap for mechanical keyboards with backlight.

First part has the Cherry MX Switch connection (+) and a small hole, so the light is directed.
Second part fits above the first one and is best printed with a semi translucent filament, so it shines through.

Some supports are needed.

The shape is similar to the Keycaps of a Logitech G610 like shown in the pixtures. 
I use it a as colorsplash on my ESC Button.