Simple 100/120 mm Extruder Calibration Tool

This is the simple tool that helps you to calibrate your extruder steps without caliper.

The cut near the end helps to easly mark 100 mm with your sharpie. Sometimes people use more filament length for example 120 mm if their printer is over-extruding. Then you should put a mark at the end of the tool. 

Could be printed in TPU for better filament alignment.