A stacked electrical connector includes an upper mating port, a lower mating port, an insulative separate portion separating the upper and the lower mating ports, and an additional metal shell covering the separate portion. The salts of the present invention are low melting and have essentially little or no vapor pressure over a wide temperature range. A server records the first event and the first time window and communicates these to a gateway at the premises. The graphical user interfaces may be displayed at a computing device located at a dispatcher site. The compressive pre-load effectively provides a negative spring constant which \u201csoftens\u201d the piezo flexure and enhances a responsiveness of the piezo flexure to low frequency vibration energy. An ink cartridge stores ink exhausted through the through hole.