Low Voltage SPD
Very different devices, from both a technological and usage viewpoint, are designated by this term. Low voltage SPDs are modular to be easily installed inside LV switchboards.
There are also SPDs adaptable to power sockets, but these devices have a low discharge capacity.
SPD for communication networks
These devices protect telephon networks, switched networks and automatic control networks (bus) against overvoltages coming from outside (lightning) and those internal to the power supply network (polluting equipment, switchgear operation, etc).
Such SPDs are also installed in RJ11, RJ45, ... connectors or integrated into loads.