Many of the key reed relay characteristics have given rise to applications not suitable for other technologies. A large number of reed relays are used in automatic test equipment. Some of these are used in the following: the automotive diagnostic test systems, functional PCB testers, integrated circuit testers, memory and VLSI testers, printed circuit board (PCB) testers, and wafer testers. Automatic test equipment, whether testing functional printed circuit boards (PCBs) or integrated circuits, can require up to 20,000 switching points in a system. With line widths running in the low nM range for the newest integrated circuits, isolation of these switching points has become more critical. The switching devices need to be able to handle digital signals in the 2 - 4 GHz range, with 50 Ω impedance, and offer very low capacitance across the contacts. Reed relays are the only switching technology that can meet all these requirements.