... <25ns. Can be replaced for the module. Product DescriptionNS1-(D, C, B) 5 series surge protection device (in short: ... Application Scope and Installation PositionNS1-(D, C, B)5 surge protective device is applicable for D,C,B grade lightening-proof, ... lightening. These series usually installed in household distribution boards, computer equipment, frequency conversion equipment, operating room, custody, ...