Where to find cylindrical lamp diffusers


Hello all,
Found these forums after watching one of Tom’s videos. Specifcially:

In that video Tom shows a number of different diffusers. I was wondering if anyone could point me to where I can find models for diffusers like the ones he shows, or maybe give me some instruction on how I might could design one myself. I’m extremely new to designing my own objects so I don’t know any tricks to do things like that. Especially the one at 9:09 in the video. https://youtu.be/QkfQri2B0PY?t=549

I’ve tried looking on thingiverse and searching for lamps / led diffusers and things like that, but can’t seem to find anything like these things. But they are pretty much exactly what I need for a lamp project I was already working on (which lead me to Tom’s video lol).