uxcell 683ZZ Ball Bearing 3mm x 7mm x 3mm Double Shielded Deep Groove Bearings, Carbon Steel 20pcs

Very fragile bearings, they do not run smooth and can feel them grabbing when they turn. most were off-centered (see attached picture) and some had a lip in the bore, preventing a 3mm shaft from going through. These are good if you want to piss someone off and see their project fail.

Theyre bearings. They spin.

I used these bearings in a small planetary gear that I printed. No issues with the bearings so far. In my case I dont see the printed material outlasting the bearings so Im not too worried about their wear resistance.