SPD Type 2 surge protection devices with QuickSafe® thermal monitoring are designed to protect against indirect lightning strikes and switching surges. They are installed as close as possible to the feed point of the electrical system. All OVR T2s consist of a base part and a replaceable protection module. They are equipped with a mechanical function display and the TS variants with a potential-free changeover contact. The variants with 'reserve varistor' (s) offer additional protection for the electrical system in that the surge protection device is not completely disconnected from the mains at the end of its service life, but an additional varistor guarantees basic protection and the system is therefore still protected until the surge protection module is replaced. They are compatible with the System pro M compact series and can be connected to them via phase rails. Mainly used in sub-distribution boards and final circuits.