Our statistics collected from many years of service show that about 25 percent of damages of electronic equipment was caused by overvoltages. The P-Z12V1 overvoltage limiter effectively protects signal line carrying away the stroke current to the ground, due to above provides adequate overvoltage protection for electronic devices. The device protects switching power supplies and electronic equipment against overvoltages. The P-Z12V1 is a passive device, no power supplying is required.