Dial indicator gauge Gregs extruder calibrate Z and hotbed

Calibrate Z and hot bed.
For installation you need:

• Plastic part published
• 1 bolts allen M4 x 20 or 25 mm
• 1 nuts M4
• 1 bolts allen M3 x 10 or 15 mm mm
• 1 nuts M4
• 1 Dial indicator Gauge 8 mm diameter shaft