Our machines are of good quality and generally do not need maintenance for several years, so our company dares to guarantee them for two years. Our machine always uses two photosensitive tubes. If the power of the photosensitive tube is high enough, one is enough. Some companies use 5.6 phototransistors because of their low power. Actually, it's not necessary at all.
Optical engraving machine 360/ set
Photosensitive bronzing machine 1000/ set
2,800 laser engraving machines/set
Baidu search "280002"