Filament clip for spools

Filament clip to fit to the side of the spool and prevent the filament unwinding.

I had some trouble with the filament breaking when I threaded it through the holes in the side of the spool. Using these straightens out the filament while in storage. As the filament has spent its life wound around the spool, it does not like being straightened for long periods and an crack. Suits 1.75mm filament.

There are two designs here, suited to the spools I have:
Round edge on the spool: 4.3mm / 0.170") diameter edge on the spool.
Square edge on the spool: 4.9mm / 0.189" wide, and fron outer edge of the spool to the inner edge of the flange 4.4mm / 0.175" then tapering down as per photots