... laser tube -More scientific design -Red dot position Mini laser engraving machines --BCL-MU SeriesProduct's description:1 ... red dot position system ,Auto-focus device Applicable industry:Mini laser engraving machines BCL-MU SeriesMould industry (construction mould, ... etc.Applicable Materials:Materials such as acrylic, wood planks(light planks,candlenut wood),bamboo ware, double color board, paper, ...