They look generically like some I have bought off Ali. I'm happy with them & cant tell the difference over a more expensive Niagra or big name, at least for my purposes.
I have had mixed results on HSS end mills, but I'd have to go back & check. Some were great, others... so-so. But carbide (based) have been consistently good. I tend to sample around Ali or buy as I need a specific size, but I've purchased some here. Specifically carbide EM's with geometry for for aluminum milling. They really work well. But they make these crazy dagger chips you have to be careful working around, I guess based on the helix angle.
https://www.aliexpress.com/store/1762279?spm=2114.12010612.0.0.1f623d4bUk1Zm5
Having an ER collet chuck really opens up the world to offshore tooling, particularly metric based where shank size = nominal cutter size. Of course you can still use for IMP cutters in your ER so its a win-win.
So, what is the runout of your ER chuck body once mounted in spindle & what is typical runout with ER collet gripping an accurate cylinder dowel/EM...?
