Printing

Printed with black PLA and “transparent” PETG; Layer hight 0,2mm. (single material also available for download)
You should be able to print without support. Maybe add some in the slotted holes.

Assembly

To mount it, remove the lamp completely from the aquarium. Since the LED has to be pushed completely off the metal rods and the LED fits quite snug. (+5mm stl file for a less snug fit)