Enhance your laser engraving projects with this versatile jig, designed specifically for engraving round 40mm keychains. 

This jig allows you to engrave three keychains at once, featuring precise slots and crosshairs to ensure perfect alignment. 

You can adjust the height to suit your keychains by using the right thickness of plywood. For keychains that are 9-10mm thick, use 2x 5mm or 3x 3mm plywood for the jig top plates, and any thickness for the base plate. 

This project is perfect for both hobbyists and professionals looking to enhance their engraving precision.