Surge Protective Devices (SPDs) provide the best protection from both externally and internally generated surges when located as close to the building distribution system as possible. Then new Siemens Boltshield QSPD series of SPDs are economical and easy to install in most panels throughout a building so that whole facility protection can be obtained. Protect your home with 65kA of surge current protection, with the option of stacking SPDs for additional protection. Boltshield offers 2 and 3 pole options to fit residential applications. Fits most Siemens panels.