ZoneMaster PRO Type 1 and ZoneSentinel Type 1 models allow users to install UL1449 3rd Edition-listed premium surge protection before or after the main building disconnect. These models, listed at 20kA, can be installed in a UL96A-certified lighting protection system. ZoneMaster features all-mode protection and options to meet the most complex protection requirements. ZoneSentinel can be used alone or in combination with a ZoneMaster to provide the lowest suppression voltages available.