Filament straightener for e-steps calibration

It frustrates me when I try to calibrate my e-steps and the filament comes out too bended. With bended filament is too hard to measure with calipers properly and it is something that you want to do with precision.

Using this straightener that is 95mm long with a 2,2mm hole, someone can measure with grate accuracy. The filament should fit snugly in the hole, if it doesn't fit then try to print at a higher percentage size (e.g. 110%)