The Standard Performance Protector incorporates a four layer Thyristor based Protector designed specifically for telecommunications applications. If the device is subjected to a surge current whiuch is beyond its maximum rating, then the device will fail in short circuit mode, this ensures that the equipment is ultimately protected.
These devices offer basic protection for Modems and are not attached to the mains earth for dissipation of energy. However, it is better to have some protection than none at all. Suitable for where one is not sure if any protection is provided on the systems you are plugged into.