parts made of fused silica for measuring or testing machines and instruments, namely, flow cells, chromatography columns, microreactor tubes, microtubes, capillary tubes, micro hole arrays; electronic power distribution or control machines and apparatus; conductors, electric; telecommunication machines and apparatus, namely, fiber optics; optical filters for fiber optics; computer network hubs and switches for fiber optics; optical isolators for fiber optics; attenuators for fiber optics; arr...