This is the last filament clip you will download. It is TOO simple. It does not care what spool you have. Stacking spools is no issue. It does not depend on clipping onto the filament. It slides on-off. It can be easily modified This has a 2mm hole for 1.75mm filament - or start from scratch and build it in less than 5 minutes. The filament holds itself by twisting & friction. I'm just surprised there are no others out there using this concept.