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The Sumitomo Group was founded in 1691 and initially dealt in copper musical instruments. - After 283 years of operation, the group acquired the management rights of Besshi Copper Mountain, making it the leader. - During the Meiji Restoration, the group achieved significant growth in production capacity through the introduction of foreign technology and machinery. - The Sumitomo Group is involved in the machinery industry, coal industry, wire manufacturing, and forestry. - The group is now a large enterprise centered on the mining and financial industries.

Main product series

Optical data links, optical and electronic devices, etc.