Designed to carry ISO filament spools with 300mm and slightly above.
Available in various sizes for spools up to 8KG.
(additional sizes added, see updates below)
The holder usually provided about 2mm play for the spools. So for a 105mm spool you'll need the 107mm holder, and so on...
The bearing sockets are a tight fit. If you don't get the bearings on, simply use a screw clamp to push them in place.
Keep in mind to print the spool holder strong enough for such weight!