42 Custom design, design, and development of computer hardware and software, electronic telecommunications apparatus and instruments, optical apparatus and instruments, optical communication apparatus and instruments, apparatus for the recording, transmission or reproduction of sound, images and data, computer networks, microprocessors, telecommunications switches, data switches, data centre switches, unified fabric switches, optical switches, opto-electronic switches, optical modulators, passive optical components, optical multiplexers and demultiplexers, optical interconnects, integrated optical devices, integrated optical modules, integrated optical and electronic modules, computer chips, computer chipsets, photonic chips, photonic chipsets, silicon photonic chips, silicon photonic chipsets, hybrid optical and electronic chips, hybrid optical and electronic circuits, integrated circuits computer chipsets, lasers, photodetectors, avalanche photodetectors; consultancy, testing, research, and advisory services, all relating to the design and development of computer hardware and software, electronic telecommunications apparatus and instruments, optical apparatus and instruments, optical communication apparatus and instruments, apparatus for the recording, transmission or reproduction of sound, images and data, computer networks, microprocessors, telecommunications switches, data switches, data centre switches, unified fabric switches, optical switches, opto-electronic switches, optical modulators, passive optical components, optical multiplexers and demultiplexers, optical interconnects, integrated optical devices, integrated optical modules, integrated optical and electronic modules, computer chips, computer chipsets, photonic chips, photonic chipsets, silicon photonic chips, silicon photonic chipsets, hybrid optical and electronic chips, hybrid optical and electronic circuits, integrated circuits computer chipsets, lasers, photodetectors, avalanche photodetectors; technical support services, namely, providing technical advice and consultation in the field of photonic chips and silicon photonic chips