LPI uses the Leader Inception Theory (LIT) for designing lightning protection systems for high voltage (HV) power facilities. LIT is one of several design methodologies detailed in IEEE Std. 998.

The new Guardian Plus air terminal range has evolved from the original Guardian CAT design and has been developed after considering the latest international research. Key elements include the effect of space charge and air terminal geometry, characteristics of long sparks, lightning characteristics and statistics, and the lightning attachment process itself.