Downlight Fixer - 90mm to 85mm

Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5135395.

Builder wants to drill 90mm holes in the ceiling before checking if they should be 85mm instead? You're the sparkie who turns up to the site and finds the big mess? No worries. This collar should sort the builder's antics.

Print them out, slide them in. The spikes give grip to 5mm of plaster to patch up the 5mm.

If you want, get a piece of 85mm pipe or something that fits inside the collar so you can smear the plaster into the gap and get the perfect circle.

And maybe ban the builder from drilling anymore holes.