The 90OPV8/R19 overvoltage limiter effectively protects signal line carrying away the stroke current to the ground, due to above provides adequate overvoltage protection for electronic devices. Our statistics collected from many years of service show that about 25 percent of damages of electronic equipment was caused by overvoltages. The 90OPV8/R19 does not affect signal quality and is a passive device, no supplying is required. ATTENTION! Before installation please read the following instructions: Any installation work cannot be led during thunderstorm. The 90OPV8/R19 requires good quality grounding installation. The limiter should be placed as near as possible to the protected device. The 90OPV8/R19 is not symmetrical and the protected devices must be connected to the "PROTECTED DEVICE" BNC output sockets. The "LINE" input BNC sockets must be connected to the transmitting lines, which may surge.