Designed for the IKEA HAVSRIS Lamp. It's threaded so it just screws on, replacing the placeholder screw-on thingy.

I published this as a .STEP file for the highest quality model. It'll take a bit longer than normal to slice but this is normal and the tradeoff that you have to make.

WARNING: The HAVSRIS socket is rated for 22 watts. Don't use a bulb rated for more than 22 watts and use a temperature-resistant material. I use the stock 3.3W and ~4.5W bulbs that come with the lamps.