Apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electrical or optical signals, especially data transmission apparatus, signal transmission apparatus, voice transmission apparatus, digital optical transmission apparatus, apparatus for transmission of communication, transmitters for the transmission of electronic signals, transmitters for the transmission of electric signals, optical transceivers, Ethernet transceivers, multiport transceivers, optical amplifiers, optical transmitters, optical emitters, optical electronic components, optical data links; data processing equipment; computers; telecommunications apparatus and instruments, especially fiber optic splice closures, mechanical splice closures, tool-less splice closures, fiber optic splice housings, fiber optic splice boxes, modular building blocks, fiber management hardware, fiber optic distribution frames; cable seals, cable outlets, cable termination units, optical device storage; computer networking and data communications equipment, especially transceivers, digital subscriber lines, opto-electrical conversion modules; fiber optic equipment, especially fiber optic connectors, fiber optic plugs, fiber optic adapters, splices, splice trays, fiber optic splice cassettes, fiber optic cables, fiber storage devices; electrical contacts; radio frequency identification devices [transponders]; software