Earlier today I printed a spool holder upgrade for my X1C and the bearings didn't fit the piece, so I got drunk and upset and made this. Oriented the way shown here, it's to test 608 bearings. Top row tests the inner diameter, bottom row tests the outer diameter. Left is -0.2mm, center is -0.1mm, right is 0mm difference from standard 608 sizing.

The holes are so you can pop the bearing out.

Keep up the great work, everyone. I love you.