... 110*110(can chose) 3:24 hours continue work Metal Doorknob Laser Marking Machine are detailed as follow:Feature:1 ... conversion efficiency, were less than 3mm deep engraving table without having to adjust focus down, one-time sculpture is 1mm ... other metals), rare metals and alloys (gold, silver, titanium), metal oxide (metal oxide may be), special surface treatment (phosphate, aluminum anodizing, ...