this is my first model, so be kind :)

this model is intended to slide over the light fixture for a fluorescent lamp (e.g. https://www.bunnings.com.au/nelson-t5-fluorescent-2-x-18w-cool-white-slimline-fluorescent-fixture_p4344802 but much older and differently-shaped)

i wanted to hang something from the ceiling, but didn't want to drill holes or use any glue, so having this little attachment/frame on the preexisting light fixture seemed like a good idea

the photo includes a smoke detector, inside my smoke detector mount ( https://www.printables.com/model/1167861-smoke-detector-mount ), hanging from this model, installed on a light fixture