Internal deburring tool - video

Internal deburring tool. By jm.workshop.q8. 11:58 video:

https://www.youtube.com/watch?v=2F8-3_kCF8U

I bought two of these from some online store. They're great. They're one of those tools where you don't need it a lot, but when you do need it there's pretty much no other way to perform that task.