The ZGG15-385Tr Modular Power Supply SPD is used for primary surge protection, and is composed of MOV power module for L N-PE，L-N protection respectively.

The ZGG15-385(3+1)Tr Modular Power Supply SPD is used for primary surge protection, and is composed of MOV and GDT power module for L-N, N-PE protection respectively.

The ZGG15-385(2+0)Tr Modular Power Supply SPD is used for primary surge protection, and is composed of MOV power module for L-PE, N-PE protection.

The ZGGF15-275 (3+1) Y Modular Power Supply SPD is a 35mm rail mounted surge protective device for various system configurations (TN, TT and IT) for use in primary power systems.