Airtripper's SLIM Pocket Filament Reel Rollers

It's a spool roller with the exact same design as Airtripper's Pocket Filament Reel Rollers, but that uses half the bearings.

All credit to **Airtripper** for this fantastic and useful design!

**Update April 7**
The description said that a piece needed to be mirrored, but it doesn't. To use this thing you must print 4 identical pieces.