automatic valves; [ electrical housings for power diodes, thyristors and transformers; ] metal-ceramic electrical conduits; insulated electrical connectors; laboratory ceramic ware, namely stirrers and vessels for chemical compounds; laboratory equipment, namely vacuum chambers and parts therefor, [ pH neutralizing apparatus for waste water, and fire traps made of ceramics, stoneware or plastic; electrical plug and socket connectors; ] remote controls for electrofusion welding machines